First of all, welcome to PC.
I'm very familiar with these sorts of thoughts. I've been a member of PC for 4 years come December. I was posting a lot on here from October 2013 - January 2014. As in constantly replying to posts and whatnot. I didn't think anyone here liked me, and thought they thought I was annoying.
Turns out that wasn't at all true. I ended up meeting my soul mate here of all places. and also a really good friend who I stay in touch with regularly. Seems the majority of people weren't bothered by me at all, and even found me helpful at times. I'm pretty sure the same is true for you.