boyfriend is mad that we aren't having sex


we've been together for 2 years and ever since I got my nexplanon implant in my sex drive is insanely low. I never want to have sex.. at all. we have sex maybe once a week if that. I feel horrible but I can never get in the mood, and it's not even like I can "suffer" through it for 5 minutes and it's over because my boyfriend takes well over an hour to cum. I don't know what to do