Assalamu alaikum - feeling lost and deeply sad, please advise

Assalamu alaikum. I know posts like this get shared a lot, but I'm really struggling and I need help, sorry. I'm finishing high school soon. I don't know how to begin, but the last two years of my life have gone downhill fast. I have no will to live; just existing is a chore and I can't make myself do anything. Every day feels like torture. I have nothing to look forward to, I feel numb, and things that used to make me happy don't anymore. I'm deeply depressed and it feels like I'm sinking with no way out. I'm failing some classes even though I used to be a top student, because I can't find the motivation to study. It's stupid, I'm sorry. I have a test tomorrow and I didn't study at all. I'm going to fail, I know it. I feel ugly, my heart feels ugly, and I worry I'll never get married. My room is a mess and I can't force myself to clean it - it feels dirty, and I feel dirty too. I keep fainting from exhaustion in public. My hands sometimes shake for no reason. I'm a total pessimist and can't seem to change my mindset, I tried. I think I'm addicted to my phone. I really try to get myself to do things but I just can't - I feel disgusting and helpless. I can barely get out of bed, and when I do it's only because I have to. I can't cook properly; when I try I make a mess and end up crying. It feels like I'm mentally broken. I spent the whole day crying today and did nothing useful. I have no friends, I'm socially anxious. I don't feel like I have any qualities that would make me a good wife or even a decent human being. I try to make dua daily but sometimes I forget and I hate myself for that. I don't remember the last time I prayed properly - is this a punishment? With everything going on in Gaza and Sudan, I feel ashamed to complain because so many children are losing their childhoods, and compared to them I have so much, yet I suffer every day. Sometimes it feels like suicide is the only escape. I see no light and I'm so lost. Sorry for the rant, I have no one to confide in. I cry myself to sleep every night and my will to live is gone. My mother has given up on me a long time ago. Can someone please give me any advice? JazakAllah khair.