I don't think I'll be able to change your mind at all. I've known many smart people who have fallen into endless pits of bitterness, and it takes a while for them to crawl out of it, if ever. But let me just throw these things out there, and I'll stop bugging you about it:
- If you're feeling depressed now, and you don't change anything in your life, then your depression likely won't change either. At least try going outside more or doing some more physical activity to try to induce some hormonal changes
- Yes, there are a lot of horrible people in the world who will harm you when you interact with them. But there are good people in the world too who can enrich your life when you interact with them. And you shouldn't let the horrible people prevent you from meeting the good people. (And to be fair, we should all try our best to be less horrible to others and strive to be good people too.)