<human>: Can you summarize the given text in a few sentences?

I've been with my girlfriend for almost three years now, and lately I've been kind of lost interest in having sex with her. When we first started dating we were having sex almost everyday, like an unhealthy amount of sex. It's dwindled down to a few times a week since then and I figure, OK, that's normal, everyone settles out of the honeymoon phase. But as of about three weeks ago, my libido has been absolute nil. We've had sex a few times but she initiated each occasion and I, lacking any explanation, just went along with it. I can still have sex, but it doesn't really feel the same anymore; masturbating feels equally good if not better.

I am deeply in love with this girl, so breaking up with her is not an option, at least not for so shallow a reason. I'm afraid to talk to her about it because she has low self esteem and extremely high stress; she might take it personally that I'm not into it, and the sex a good way for her to relax. We've tried being kinky (minor roleplay, lingerie, etc.) but that isn't working and I don't think I want to get more kinky than that.

I get along with this girl in every other facet of life and I truly believe that we are meant for each other, but how can I get my libido back? And if I can't, what if anything should I tell her? Please help.
<bot>: I don't enjoy sex with my girlfriend anymore, how do I regain my libido, or cope if I can't?