Not feeling it...

Lately, and idk why, but I have had a huge drop in libido. I've been on the pill for months now and I've never had a problem but lately my boyfriend would kiss me and touch me and I would feel nothing. It's not like I'm not attracted to the guy I love him to death I just feel like something is wrong with me for not getting into it. Usually it ends with him finishing himself off because he can tell I'm just not into it. It's never ever been like this and I feel so bad for him. Any tips for becoming horny or any idea why this is happening!?