What are your interests? I had to take this depression group when I was younger and one of the things they made us do was make a list of "pleasant activities" or just things we like (I had some really sad stuff on there: one was that I liked iced tea). Afterwards, we were supposed to do at least one pleasant thing every day and keep a graph of our mood.
It ended up being a good exercise, thinking about it now, because it's amazing how much better you feel when you do things you like, even if they are really simple things.
I kind of realized how much I put myself down. It's like I tell myself how much I suck before anyone else can, to the point where I don't want to do anything. But everywhere you go there is always at least one person who has to piss all over everything to make themselves feel better.
I remember some people talking about this guy they knew that snowboarded and how that was all he ever talked about. They were saying how one time they went snowboarding with him and he sucked so bad. They were talking about it afterwards, when I was there, and they were laughing at him behind his back.
I really hate stuff like that. I despise that about people. Seriously, who says you have to be an expert? What's wrong with being enthusiastic about something? Why can't a person just enjoy something without being treated like a wannabe for doing something they like?
Anyway, don't judge yourself, if that's what it is. You don't have
to be good at something and you can still like it. You can like sitting alone in your room and playing guitar, because you find it relaxing, without aspiring to be a rock god. Ultimately, hobbies are for yourself, not other people.
If you are looking for some ideas for stuff to do:
I really need to take my own advice, as well...