How can I gain perspective?

I'm 28, been in several relationships but I just can't seem to be strong in them. I've had nerve problems since I was a kid and am currently taking paxil for a social anxiety disorder.

I'm currently seeing a very cool girl. We are taking it slow since both us have rushed in too early before. The problem is I just can't get comfortable.

When ever there is the least bit of confusion about how she feels about me I tend to dwell on it endlessly until she does or says something to reasure me. She can't be attracted to this aspect of me and I'm afraid it will push her away.

I can't stand the pits in my stomache, and the constant dwelling.

Does anyone know some calming techniques or at least a consolling way to look at it? I should be happy with this, and enjoy the time I have to myself. I'm worried having her in my life will become my all encompassing purpous again like I've done with past relationships.

I just wanna calm down. please help.