Advice?

Hi, sorry if this post goes on forever but i wanted to know if anyone has any advice :/
I have been with my BF for over a year now and at the start i was on the pill and we seems to have a lot more sex then. I then went a got the implant contraception as i wasnt that great at remembering to take the pill. For the past few months since i got the implant in we havent had sex at all. I just seem to not be interested in it at all and it seems to be too painful for me. I always stress afterwords about being pregnant which also puts me off even though we also use condoms. 
I feel really bad as i keep putting the idea of sex off as im either not in the mood because of contraception or else nervous because of pregnancy.
I feel like i should change my contraception because it is making me feel like this. Has anyone any advice on how to deal with a situation like this? As i would like to have a relationship like we were at the start again :/