Feeling terrible about myself and my life

I have no friends, never been in a relationship, my family thinks I'm wasting my life and keep making fun of me for having no friends. I feel like I mess up every single opportunity I'm given to make friends or make my life better. I feel like I'm just a horrible person to be around, but don't know why. I'm stuck in a low-paid job working unsocial hours, that I hate. I am working really hard to start my dream career but I'm finding it really hard to stay motivated when I feel like shit 24/7. I am starting to doubt my life is ever going to get any better. I just wish I had someone who actually cares about me and supports me, but I guess that person doesn't and will probably never exist.