I agree with Odee in that your gf clearly prefers your company.

You do not have a jealousy problem. Rather, your problem is in your expectations of your feelings. You expect yourself to forgive. It is in general tough to meet such an expectation, and with ocd, it may simply be impossible. So the thing you truly need to forgive is, paradoxically, those obsessive thougjts running in your mind. Plus, paradoxical approach is helpful in that it builds up to desensitization. So next time those thoughts cpme to your mind, do not chastise yourself but rather say hello to them. "Oh, thoughts about that painting, hello. Long time no see. Make yourselves comfortable - I sure have missed you guys."

...

Eventually you will have had enough to get bored.