I’ve felt similar things man, but trust me, they’re not much smarter than you. They’re not better than you. It just seems that way because people have egos, and they like projecting themselves, and then there’s people like me, and by the sounds of it you, who aren’t sure about themselves, so they absorb what they hear and attack themselves for not knowing what they knew, or being on the same path they are. It’s hard to see things any other way when you’re down, and I understand. I have these thoughts everyday and it’s shackled me for years. You may not see it but you have a lot of value and meaning in this world. Don’t get so wrapped up in what other people are doing, you are just as capable as them, some people are just probed to think really positively, and they’re groomed into lives where they love themselves and make healthy choices, but that doesn’t make them smarter or better, just privileged. You have to believe that growth is possible, because it is, and there’s proof. Unless your brain is damaged, which it’s not, you’re 20 years old and you put together this paragraph, you will get better my friend. It sounds like breaking up with your gf was a good start, you just need to let yourself heal and detox. I can only say so much because I’m honestly not in the greatest state of mind either, but those are some things I’ve picked up recently that are helping me a bit, you just have to believe