<human>: I'm 22(m) and my gf is 19. I'm having an issue with sex with my gf & could really use some advice from you guys. 

A little background info; we have been dating for over a year and live together. The first year our sex life was great. She would want to have sex very often, and we would almost every night. I would always initiate, but she sort of made herself available, if that makes sense. 

As of the last 4 months or so, we have had sex maybe 10 times or so. That may be an exaggeration, but we honestly don't have sex like we used to, and I feel like she's never in the mood anymore like she used to. Everything else is great as always. No complaint anywhere else honestly. We hang out, flirt, eat, make-out, but just no where near the amount of sex we used to have. Blue balls is too common of a problem these days. 

Does anyone have any clue why this may be? I do get that I have a high sex drive as I have had this issues with other gfs. If it were up to me, I would have sex nightly, but I get this is a bit much. I would be happy with 3 times a week. Is this too much as well? I don't know how much sex is normal sex. 

Some additional info: She is on birth control that the gynecologist said may lower her drive. I really can't think of any external factors that may lower her sex drive other than that. Thank you guys.

Can you summarize the given text in a few sentences?
<bot>: GF seems a lot less interest in sex and our sex life is nearly dead. No idea why this could be or how I can kick things back up.