I go through this periodically, mostly when I'm exhausted (and our summer reading program at the library is a major contributor). I'll start taking every minor thing as a major criticism and questioning my own abilities at social interaction. And then I start looking for reassurance in stupid ways that probably make matters worse.
This time around it was simple. RPing is very new to me and I was surprised how much I liked it and in the beginning there were some lovely meaty threads. Recently, all my threads went dead on my almost at once, and despite the fact that I know other people have lives (and many more characters than I do) I couldn't help wondering if I was doing something wrong.
So, I tried, in all the wrong ways, to get things going again. Mostly in an open mouth, insert foot up to the knee sort of way. Not likely to make things better, in fact it probably just made things worse.
Last night things got so bad I wrote a prompt that was about 2/3 in character angst and 1/3 venting about the way things were going. I regret it now, and when I got up this morning I thought I'd take it down, but I don't know. It's very much a reflection of the character in my head (even leaving out the other issues).
And now, I just don't know. Maybe I'm lousy at RP or just going through a lull. I don't have enough experience to judge and maybe I'll look at this six months from now and laugh.
For now, I've banged my head against that brick wall once to often. If I've been bugging people too much about playing, don't worry. I've stopped now. I've made my request, if you want to play with my characters, they're right there in the open threads I've attempted to start, or in the threads we started. If not, it's not the end of the world, and I'll try to stop taking it personally or feeling like I screwed up somehow. Unless I did, in which case you should tell me so that I can try to fix it.