I feel depressed after everything i do?

for as long as I can remember I've become more or less of a recluse due to anxiety disorders and these days I have realised I wasted my life and I want to get back to normal. Problem is, after doing things in public I always feel depressed for no particular reason and just want to go back to hiding out at home... is it normal to feel like that? how should I get over this? The other thing is, obviously I don't have any friends because of this too. I hang out with people and then feel depressed for a long period of time and can't bring myself to talk to them...