Sex drive HELP

I just started a new relationship and we have had a few very good sexual encounters. I know that I’m super attracted to my boyfriend and find him to be super sexy. However, recently my sex drive has just plummeted. I can’t even orgasm through masturbation anymore. I have no idea what to do because I want to have fun with him, but I’m just not horny enough. It also hurts because after we try I can tell it really bothers him. He says it’s fine and assured me he’s ok and doesn’t want me to feel bad, but I can tell. What the hell should I do?!