Anxiety overdrive

I really hate being alone because once I’m by myself I can’t stop overthinking about all my mistakes that I’ve ever made and i constantly question whether or not people actually like me. I don’t know what to do anymore, it’s like the simplest things set me off into a downwards spiral of thoughts that physically hurt my brain and make me want to just sit in a corner and give up on life. I’m really confused and anxious at the moment about life. I don’t know what I want and I can’t make any decisions because I change my mind so quickly. I constantly think about what a mess I am and because of this I’m scared people are going to walk away from me because I’m too difficult to deal with. I’m up and down all the time and I don’t want people to get sick of me because I’m really trying my hardest to be a good person but I feel like everything I do makes a horrible person. Someone please help I’m using every last bit of energy I have.