1. Teenaged girls generally experience a lot of distress around their developing bodies and are being told that this perfectly normal discomfort is a potential indicator of inherent transness, and those of them who will be gay or bisexual adults are likely to wrap in sexual orientation discomfort

2. Teenaged girls are well known to pass around ways of expressing very real distress and have been known to do that for at least hundreds of years- eating disorders, cutting, etc are all culturally legible ways for teenaged girls to express their distress, and this is likely no different

I don't think that's a helpful question. Detrans people were trans by every meaningful metric we can imagine. The question is what you're feeling now, what strategy will work best for dealing with that, the severity of the current problem relative to the risks of each option, and the pros and cons of each potential approach to transition. I don't personally believe there is any soul level difference between people for whom transition is the best choice and those for whom it isn't. More helpful questions are whether you need to transition, whether you think the risks are worth the outcome, etc. Assuming you're an adult I think it is generally most helpful to approach this not as a matter of feelings but as a decision about potential medical intervention.

I deal with moderate sex dysphoria that I don't think would be solved or fully alleviated by transition/I've weighed my options and the cons of transition do not outweigh the pros for me personally. I do not refer to myself as cis but that's how I describe this kind of thing when asked.

I'm a lesbian and I "crossdress" every single day and enjoy having the ability to pass when I'd like to. Nothing about ceasing transition necessitates changing your "gender presentation" (I hate that term but I'm sure you get what I mean) and it's really disheartening that so often, female detransition narratives include this sense of obligation to be feminine due to being female. For me, the whole point of desisting/reidentifying was to get away from a paradigm where being female limited the range of behaviors and ways of living available to me.

Two things can be true: bathrooms for women especially can be designated as being specifically for members of the female sex due to matters of safety and of comfort being in any state of undress around males, AND there can be some people, detrans and not, who are difficult for most people to quickly and accurately recognize as the sex they are. I am butch and generally avoid women's bathrooms to avoid making other women uncomfortable, which is unfortunate because using them is my birthright. But allowing males in so that I can go unchallenged is not a worthwhile compromise imo- I think it is baseline good for women to feel comfortable challenging the presence of someone they believe is a man in the bathroom, and I also accept that sometimes those women will be incorrect about who is a man. But these are the kinds of social problems that are connected to transition, but they don't arise from it- I've never taken testosterone, but I'm regularly mistaken for male. There's not much anyone can do about that. Ideally, we would address this issue through awareness that female people can look a lot of ways, which ironically is not helped by women feeling uncomfortable calling out the presence of real and obvious males in women's bathrooms.

I think most people who claim they have an easy answer here are living in a fantasy land. But given how widespread transition has become in the west, I think that going forward requiring businesses to have one single stall or both-sexes welcome bathroom in the way they are required to have a place for women to use the bathroom (in addition to their single sex bathrooms) is probably the best compromise ssolution.

If it is any consolation, you were never going to look like your 13 year old self again anyway! We change so much during our teenaged years, especially, but also forever. If you had gotten into a car accident and been disfigured sometime in the last 11 months, or fallen on your face and left a visible scar, that too would have changed your appearance forever. But life is long and you have a lot of it left to live, so my advice would be 1) to look forward as much as possible and 2) to maybe seek out other kinds of narratives (stories, movies) about lifechanging events that people have encountered outside of transition. It might be really emotionally helpful for you see how other people have experienced those changes, felt about it, coped with it, etc- every real life story like that is further proof that people can experience really big things and make it out the other side to live long, happy lives. What happened to you was absolutely not your fault and it cannot be changed, but the human body is remarkably strong, and you are in a period of time when your body is capable of recovery in ways you will never experience as an adult. I really think you're gonna be just fine!

I think there's a real possibility that your friend was always kind of like this and that you just notice it a lot more now that you see your friend as a member of the sex they actually are, at the same moment your friend is transitioning. A lot of the social impetus in trans spaces is to ignore people's sexes, to the point that some people train themselves to just not notice. I can't know for sure, but there's a good chance you just notice this sex-typical behavior now, and are bothered by it.

Either way, it sounds like this person isn't someone who's bringing you any joy or fun or good times anymore. 18 years is worth at least having a talk about behaviors that are bothering you, but you are not obligated to keep hanging out with someone unpleasant just because you've known them a long time.

Why did nobody explain to me the difference between insecurity/body dysmorphia and gender dysphoria?

Because a lot of people have a lot politically, emotionally, and financially invested in the idea that there is a fundamental difference between being obsessively unhappy with a non-sex specific trait and being obsessively unhappy with sex specific traits. There is no thick, solid line between gender dysphoria and other forms of emotional distress about the body, which is part of why the rate of eating disorders, self harm problems, etc is so high among people who are uncomfortable with their sex, and is part of why you see this problem most in exactly who you'd expect to see it in- groups of people who experience a lot of anxiety around their bodies and sexualities.

A lot of detrans people transitioned because they believed in the ideology transgender people have been collectively pushing (that gender is about identity, that one can factually change genders, that HRT is the only treatment for someone experiencing gender dysphoria, that HRT doesn't cause health problems on its own, that surgery and hormones make you a different kind of person) and no longer believe it. Detrans people and trans people will continue to have problems until disagreement with the ideology that a lot of (though obviously not all) trans people are pushing is not seen as hateful, and we are a long way away from most trans people I know being willing to accept that some other people outside of the ideology think "man" and "woman" are names for halves of the species based on sex and not identity.

People mistaking you for MTF does not "defeat the whole purpose" and neither does choosing not to engage in typical femininity with women's clothes, etc. The "purpose" of desisting for me was twofold: firstly, to accept myself as the female person I will be until the day that I die, and secondly, to free myself from the arbitrary and harmful notion that being female means I need to be a certain way. In that second goal I wrapped in just letting go of allowing gender to have this major importance in my life when nothing I called myself would change who and what I am. So what if someone thinks you're MTF? People think I'm all kinds of things on a daily basis. I never transitioned physically but quite frequently pass for male, especially during the winter. How other people perceive you has no bearing on how detransitioned you are. Hope this helps! Learning to let that stuff go should be a huge part of this process.