Sexless relationship at age 19

Aubrey
My boyfriend and I are 19 and we've been dating for a year, we have little to no sex at all like once a month. When we first started dating 
 we had it like twice a week.... I don't desire sex at all... Nothing whatsoever, in the beginning it bothered him but now I don't think it bothers him anymore. I feel bad but I just don't feel like doing anything with him and if I do it feels forced and like I'm doing it just to make him happy. What do I do?