Implant in arm and losing my sex drive!

I've been with my boyfriend for a year and a half, had my implant put in about a year ago. Since having the implant I have felt like I just can't be bothered to have sex anymore. I used to want it all the time and I used to get wet really easily but now I never feel up to it and it's hard for me to get wet now. When we do have sex I rarely enjoy it much and I just don't have the drive to put much effort in.
I do really want to have sex with my boyfriend, I am only 18 so I don't think it's right for me to feel this way and it is putting a strain on my boyfriend because he is thinks he doesn't turn me on and thinks that I don't find him attractive.
Does any one have any advice? 
Is there anything I can do or should I look into changing my birth control?