My bf prefers large breasts and doesn't want to sleep with me

I am dating my boyfriend over a six months now. I was the one who initiate a first move in the bar where we have met and gave him my number. After few months it slipped through his mouth that he likes girls with large breasts and mostly all of his girlfriends had really big ones. Well I felt like shit because my ones are 34A but tried to deal with that by myself. He said he wouldnt mind and would like me to get breast implants but that it is not mandatory to him. My breasts have really nice shape, my exes always liked them. I have a great round ass and I have always dated ass guys. So they were always crazy about my ass especialy in the bed. I can really say the difference of how my exes were horny about me and how my current boyfriend is. He doesnt have problem with errection during sex but his sex drive with me is very low to what I would prefere. Last three months it is usualy me who initiate sex. Usually he tells me not to touch him and that he is not in the mood for sex. He wants to sleep with me like maximum once a week. On the other hand even though he doesnt want to sleep with me he enjoys doing oral sex and other things for me. Am so horny when I am with him and it makes me frustrated. To sleep with him more than once a week I have to try hard to turn him on. About his feelings. He really fell in love with me and it shows. He can be quite jellous of others guys that are chasing me. He tells me how sexy I am and the fact that he is not in the mood for sex has nothing to do with me and that he likes being with me even if we dont have sex. Anyway it is really hard for me to be in that kind of relationship. When he didnt want to have sex I have asked him if he masturbated that day or the day before. Usualy he said yes. Which means he has a sex drive but not with me. I asked him if is it because of my breasts size and if he watched such a videos. He said he masturbates to random videos and isnt bothered about breast size. Also said to me he preferes real sex than masturbation because orgasm is better. I asked him if he could maybe next time wait for sex with me instead of masturbation and he said yes. Anyway this week again no mood for sex. So I checked his browsing history and he was looking at videos of really large breasted porn star Katee Owen. This all really hurts me and dont know how to deal with fact that I am not his type and that he doesnt want to have sex with me. A was always so attractive to my exes and even now there are guys crazy about me. I really dont know what to do and fell like I have to break up with him because I cant handle this. I would like to know if his low sex drive is because of my small breasts?