Libido MIA in relationship

My bf and I started off having sex like crazy, and I do mean a lot. Months have passed and my libido has diminished, reappeared and finally disappeared (this has happened before but I was single). Now this could be due to the amount of medication I'm on, it could be due to the fact that I suffer from a long-term depression, or it could even be caused by the contraceptives I started taking about 4-5 months ago. My bf has been feeling insecure about my lack of sexual attraction/craving and thinks it's because of his body. I know it isn't and I've told him this many times. Idk how to deal with this, Idk how to connect that pleasure centre of my brain to my body again. Idk how to get through this with him because I feel guilty for not being able to "turn on" when I want to. Any advice?