i dont like having sex anymore

my bf and i of two years used to have sex almost everyday at the start of our relationship but this past year i’ve had zero sex drive. we haven’t had sex in about 1-2 months and even then it would be 2-3x a month. i don’t know why i don’t feel like it anymore. the only way i can get it on is when i’m drunk, but even then i still really don’t want to, and i feel bad because my bf asks me everyday and i always make up an excuse. i’m wondering if it’s because the birth control i’m taking (depo)? i don’t feel anything and i do love him but i never want to have sex with him. the thought of it grosses me out at this point i don’t know what to do or what’s wrong w me