I am not one to call out to other women for advice, but ladies i really use some tips and pointers. (mature aspects only)

I have been in a relationship for seven nearly eight months now, things are starting to get a little dull in the sex life. Now are sexual activity has slowed down, which i can understand but some things are a little strange.

Recently over the past few months she has not been as sexualy intrested in me as she used to be. she has started wearing pajamas more often and covering more up so I fear she is concerned of her size, so i started to compliment her more and try and show a little extra affection but that doesn't seem to be working?

Now I have some pretty good knowledge and experience, and she tells me that I do my job perfectly every time and I must be if she "cums" at least twice each time. But she has been complaining about pains in her stomach and vaginal region, fair enough not every time is perfect but she tells me when i am going wrong. She has gotten slightly tighter as are sex lives slowed down but she complains that I am too big for her and it hurts, now I could really use a few pointers to get back on track and spice things up again? I have tried a few different ways now but she ain't telling me crap, any pointers on this?.