Hi, Alliy, we're glad to have you.
You might get more of a response in the Getting To Know Each Other forum, just below this one, but never mind that. It's only one thread, after all.
You'll find us occasionally tactless and sometimes we seem frustratingly stupid. Keep your cool and give us the benefit of the doubt, bearing in mind that that's how you seem to the NTs in your life.
I was dx'd a lot younger and knew why I struggled so much and I still came out with confidence issues for a while there. If you have low self-esteem (you probably do; being beaten down so much and feeling so misunderstood is probably why you're depressed), let me share my own story with you (in abbreviated and sanitized form). I had lost most of my confidence by the time I was your age, and I was really depressed a lot. What helped me was keeping a diary. Paper doesn't judge, doesn't tell you to shut up. Getting the feelings out, you'll find that as much as they hurt, they seem kind of stupid when you say them. You'll be able to go back and look and spot apparent contradictions. You'll be able to have a written record saying "I believe I will fail at this endeavor" to go back and look at after you succeed at that and when you think you'll fail at something else. And when you get it out, you can look at it for what it is, not what you're blowing it up into.
Not that I'm qualified to dispense medical advice, but I was depressed to the point of delusions, and it was probably for the same reason.
Oh, and care about something. Duh. But seriously; if nothing in your life has any point, how can anyone expect you not to angst about how pointless it all is? Doesn't matter what you care about, but it has to be something you can succeed at or fail at (and something you have control over your success in), it has to be something you want to succeed at and you have to get some kind of feedback for success. For me, it was posting crappy fanfiction on the Pit o' Voles. Success was getting good reviews; failure was not getting good reviews. (It's always iffy to base your own success on someone else's reassurance, though. You could be the next Tolkein but if your audience likes humor...) I could exercise some control over my own success by writing what people liked, using correct grammar and filing each story correctly.
Anyway. I guess what I'm saying is... scroll down. Way down. It's right above the blue hippo.
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I'm using a non-verbal right now. I wish you could see it. --dyingofpoetry
NOT A DOCTOR