Mental illness is a recursive loop

Some background on me before I get to the actual post, for context. I'm a 14 year old, nonbinary kid who's been suffering from severe depression, self-harm, suicidal ideations, anxiety, panic disorder, and ADHD for about six months now. I was in inpatient for a week after my parents found a suicide note I was planning to use later that day, and have been in outpatient for about two months now. Medicated, treated, talked to. Nothing seems to be helping. The issue, I guess, is that I've beaten my self image down to smithereens, over and over and over again, every day, and I can't stop doing it. Everything I do that other people praise, I deny, everything they say is good about me, I can attribute it to something else. In the rational side of my mind, I know this is so fucked up it's not even funny, but all those "No, it was X other thing, not me." or "Anyone could do that." or "You're just flattering me" statements still ring so true in my head. I'm so tired of feeling like shit and not being able to let go of feeling that way. My depression begun when I realized that I was A) Gay as fuck, and B) Not cis-gender, and I couldn't really deal with it. My self image went down the drain, and I started to cling to the horrible thoughts I've had about myself. I did this for months and months, and it just got worse. I went from miserable to barely being able to get out of bed in the morning to self-harming to upright suicidal to planning on dying. By now, those thoughts about me are all I have left of myself to cling to. I don't know anything else, those are the only real facts in my world. And everyone keeps telling me to let go of them, like it's the easiest thing in the world. I know I should, and I'll be better for it, but I'm so scared of what 'better' even is. I like to hold on to what I know, I don't like the unknown in any form, and of course, a me without this everlasting depression and this fucked-up brain is something I can't even imagine. It's a loop everyone expects me to just jump out of, and I can't. I don't know how, I don't know where to start, I don't even know if trying is worth it... I need help, I need help so bad but there's nowhere to get it that works. I don't even know why I'm writing this, really, but I just hope there's someone out there who'll understand what I'm saying.