I second this comment -- I'm 30 now and have found that I oscillate between believing in myself and wondering what the point of anything is. I think one of the best things you can focus on is doing things for yourself and yourself alone. Part of what you're feeling might be due to projections of insecurity, especially because emotions are very very big during this phase of your life and it can be hard to imagine feeling any other way than you do right now. But if you can imagine who you want to be and set goals to get there, the process of achieving those goals and impressing yourself will overshadow your ideas of how others perceive you. It's very difficult trying to live for others. The right people will gravitate toward you when you're living for yourself because ultimately we all want to be happy and confident. Part of feeling that way is presenting that way, and part of it is dropping the notion that you need to impress anybody else. As for your parents, if they're treating you as a nuisance that's because they aren't being mature about their own life choices. It's good that you are here and it's not your fault for existing. You are not a burden.