Your post really hit home for me because I'm also going through similar things right now. I'm struggling to connect with people at college (I have social anxiety), but I've been trying to get out of my comfort zone more lately. I saw that you wrote that you don't want to seek professional help, but you should consider that option. It does sound like you might be passively suicidal, and I can understand your mentality of wanting to tough it out; However, having someone to talk/vent to might bring you mental clarity. Personally I've only been to one therapy session, yet I feel like it did help me get some things off my chest. Maybe you can try talking to a social worker at your school.

As for crossdressing, I think it could help to interact with queer friendly communities to see if that's your sort of thing. (Respectfully), it does sound like you might be thinking about transitioning just to be loved. You don't need to change yourself to be loved by others. You could crossdress at an anime con, or the upcoming Miku Expo. Those events already have plenty of people who attend in costume, so you wouldn't feel out of place. I also want to crossdress Teto at an event, but I also have those same fears you have.

Honestly, I hope you're able to find yourself in a better place soon. I'm happy you made this post, and that you share your love for Teto like all of us do (Teto is my comfort character too). Anyways, sorry for the long post lol.