I think we all feel like that at some point in our lives, I know I have :c
you just got to look on the positives, stop being overly analytical and try and focus on something you enjoy. The world can be a very scary, unhappy place for alot of people, but I mean you're still alive, you've still got you're health. I don't know you personally but I'm sure you've got family or friends who love you. Just think positive, things DO get better.