No Sex Drive

Cathy • Asexual and proud.
My boyfriend and I have been together for 5 years and I just have no sex drive anymore. I never feel like having sex, and when we do, I have no energy to touch him or kiss him in the neck or any other things that would please him. 
I really want to increase my libido. 
I'm on birth control and that could be a factor but even before birth control, I just was never all that horny. 
This is ruining my bf's self esteem and ruining our relationship. Please help!