My boyfriend doesn't seem to be as interested in being intimate with me?

[Michelle]

I have been with my guy for almost three years and when we first met we were more friends with benefits and grew to know each other and then we started dating. We have been together for 3 years almost. I am the kind who likes to be held and kissed even if not on the lips i LOVE getting kisses on my cheek or my forehead. We used to do it like 4-5 times a week and it was like that for a very long time. Now i get it maybe once every other week if even that. I have PCOS so it hurt me to have sex a lot which is why it kind of stopped for a while but after all of my medicine to help get it under control and to help the pain it seems like he just doesn't want me anymore. I have to literally beg him to do something with me. I have to fuss before he kisses me and it is just plain exhausting... I am a full time student and i work a full time job to pay bills and he works night shifts as a nurse. He always comes at me saying i never understand why he is tired but i do .. i go to school 5 days a week from 8 -1 and go to work everyday from 1-8. So i love to spend time with him when we can and during that time i would like to be kissed or hugged with out begging for it. I try and kiss him and do things i know turn him on but he seems to just push me away and say he can't tonight or he is to tired. we got in a fight one time because i asked why we never did it anymore and he told me he wasn't going to throw a party just because I want to have sex with him. Is it me? i just don't understand its depressing me