I feel as is you don't really dislike conventions, instead you just haven't found out what to do while at the convention. At least, something that you don't feel the voice in your head telling you that everyone is staring at you. Does that generally happen just at cons? Or any place in general with many people?
Back to the topic: Don't give up. Look around for small conventions you can go to as those are normally not as crowded and you're bound to just see people multiple times. That was how my first con was, and it was..Well nerve-wracking since I was afraid of asking people if they didn't mind a picture. But that is just shyness, and if you don't tackle it then you'll always be afraid.