Feeling pretty unwanted. help!

me and my boyfriend have been in a relationship for 9 months now and for the past 3 months he hasn't initiated anything sexual and if he has its always been after iv started an argument about it but then it just goes back to the same thing. its making me feel so unwanted, disgusting and suspicions that he's cheating. i suffer with anxiety already and that doesn't help even though i hate to believe that he is cheating. iv tried to talk to him about it but i just got the 'iv just come out of the "honeymoon" stage and you havent yet' but i just know its not that. any ideas??