antidepressants and sex

I need help. Ive been on antidepressants for about five months now and my partner and I have been having sex but nothing feels good, it's like I'm in the mood but my body is not. We use a lot of foreplay and I really want to understand what's going on and what I should do to help. I've been thinking of going on the pill but I don't know if it will help or make things worse.