So I've always been a fairly anxious, obsessive kind of person - very unremarkable in itself, I know - but very recently I've begun wondering if it's something more, for various reasons. However, I'm also very nervous about consulting a doctor: I don't want to waste their time just because I'm determined to find something wrong with me.

My primary reason for suspecting the condition (or something similar) is a lot of intense intrusive thoughts about my relationship. In fact, I only researched OCD in the first place because other conditions suggested by friends didn't seem to fit, and I'm convinced my mother has OCD: and the parts regarding intrusive thoughts in relationships really resonated. I'd just assumed I was a horrible, obsessive, crazy girlfriend before, I'd not attributed it to mental health. My younger sister also does have trichotillomania, so I feel it isn't entirely implausible, at least at a genetic level? I've had (different) issues before.

Anyway, my relationship. It's been more than two years, and it's great. Very comfortable, very loving. When I'm feeling myself it's pretty much perfect (as much as anything can be). However, every few weeks - it's been a pretty constant cycle since me and my partner got together - I build up these horrible worries that I can't shake. They range from me being convinced that I'm being too annoying/clingy/intense and he's going to leave me, to me thinking I'm emotionally manipulating him and forcing him to stay. I've been worried that he only likes me because I'm convenient sex, or that I only like him because he's a nice anchor-point against my more tumultuous emotions, and that actually we have very little in common. It's really all sorts; this barely scratches the surface. We don't live together, and sometimes I'm able to wait once the thoughts reach fever-pitch, but often I've gone over to his house, sometimes very late at night, because I need the reassurance right then. I often write long 'letters' to him about it, so that I can ensure I get everything out, which I will then show him. He is always incredibly tolerant and understanding, he reassures me, and he will generally agree to make any changes that I think I need at the time.

The trouble is, of course, is that the more I need these reassurances, the more I feel like the crazy girlfriend I'm trying really hard not to be, so it's a vicious cycle.

Now, regarding seeking medical advice. I was planning on making a doctors' appointment and explaining all this to my GP and seeing what they say, but I'm really scared they won't think that it's remotely significant. Plus, I do feel a little like I'm a teenager asking for advice about boy troubles. It also doesn't help that I'm currently in one of the nice parts of the cycle: I got very worked up after Christmas during which I became convinced he was going to leave me, but following a good chat/cry with him I'm feeling happy again. The one trouble with this is that a) I don't want to wish it back and b) it kind of feels a bit fake now I'm not feeling it anymore.

Any advice/reassurances/similar experiences?