I think roleplaying has always been more about the social interaction if you come at it from having done table top RPGs. I mean, I hung out with some strange people in my time, people I probably wouldn't have if it wasn't for RPGs. Half the fun of game night was going to someones house, ordering food that was bad for you, drinking and laughing your butt off at the dumb jokes and the various interactions. I think if you come at it from a writing perspective, it's a little more difficult. Mine kind of coincided. I was into RPGs a little before I got into writing when I was young. Writing is typically not a social interaction at all. It is lonely, quiet work. If I didn't have that table top RPG experience I think I would have gotten lost a bit when I first started.
My advice would be to do what you are already doing, join the group games. Get into the OCC and chat away. My first RPG experience was a PBEM game with a person who'd written their own RPG. It was an established group and I kind of felt like an outsider. But they would do an IRC game ever few weekends and getting to chat with everyone, as well as chatting with the main woman writing the character mine was dealing with in IM, I really got to open up and take in everything. If you focus only on the game and the character, especially only yours, you are going to have a miserable time. I've been in those group games on some boards were I didn't put myself out and I grew to dislike the game.
I think you have to approach things from a joint perspective. If you were writing a joint story for something, it would be a collaboration. You have to have given and take. To me, that is the fun of things and I think you have to learn to enjoy that. I know a lot of people what a story that is set on rails, they want what they want. To me, I've come to love the curves my writing partners can throw into a story, to me it makes a better story. That's the point I think of these types of one on one games. A lot of my ideas are vague, a starting point. I probably could design it into a full fledged solo story but when I get a good partner, those stories blossom into something totally unique. I get perspectives and ideas I would never have thought of because I'm limited by my point of view. Yes, it does come with some inherent risks, but I think it's something you need to embrace.
I think you do need to look for people who's style you match. You need to talk with them. Both about the game and just stuff as well. When they throw out an idea, look at it and see if it adds to things, what interesting paths will it take the story. Don't just dismiss it because it's not yours. It can be difficult, you will probably have to write and drop a few stories. Be honest with your partners and dare. That's my best advice.