I Feel Guilty

My relationship with my girlfriend of 5 years has been in a tough spot for a while, for a variety of reasons. And I have been unable –or unwilling– to talk to her about it because she's been going through a lot. In the process, though, something inside of me has died. I feel constantly numb, like on autopilot. According to my therapist, I might have fallen out of love with her...

Which makes me feel like an awful person, and I've been pretending everything's fine to protect her. But I don't know for how much longer I'll be able to keep the illusion up. I've been giving in to sex and demonstrations of affection because my therapist says it might help me reconnect with her and fall in love again. But I don't feel like its working, and now I feel even more guilty because of it. Like I'm using her or something.