The "not bothering to speak when being yourself" thing might be a form of not being confident enough to be yourself.

"Be yourself" means don't mind sharing genuine info about yourself when the opportunity presents itself. Don't make anything up to make yourself seem more interesting, and see yourself as interesting the way you are. And you hope that something will "click" with the person you're talking to. You don't have to be compatible with 100% of the people you talk to, but you want that person to like you for yourself, no?

Make a list of things you enjoy and practice presenting them in such a way that they're interesting. Don't present them in the "I'm lonely and boring so sit at home and do X to pass time, otherwise I'd be bored out of my mind"
It could be anything. Hell, sometimes I try to make "I play video games" sound interesting.

It's not "I play video games at home by myself to kill time because I don't have any friends or anything else better to do"

But rather "Video games have always been a pretty big part of my life. I guess my dad decided they would be my source of home entertainment when I was little, and I liked them so much that I still enjoy them now. I picked up game X yesterday. The story is about Y and it has features A, B, and C"

Both statements are probably true, but
In the former, I'm assuming that there's nothing interesting about me and nobody will ever like me for myself
In the latter, I'm "being myself" by naming a real interest as well as specifics about it

Go out in public to do things that you could do at home sometimes, like reading at the park or bookstore. The more time you spend out, the better chances you have of a random non-creep approaching you. A lot of guys find the girl by herself more approachable than the one in a group anyway.