Insecure about my breast

I'm so insecure about my breast :-( I've been seeing this guy who is a total freak we haven't slept together yet but I can tell by the way he talks about it he's into like that 50 shades of grey type shit and so am I. But me being insecure about my breast has been holding me back from being as freaky as I like and I know the only way I can make him happy sexually is by being freaky but I need more confidence in my body. I have smaller breast and they're very perky but the area around my nipples get kind of big sometimes like if I'm too hot I usually try to have sex in a cold room but that can't always be the case. I think this comes from my ex making fun of me after we broke up many yrs ago and I never noticed it before but ever since then I've been insecure Has anyone had this issue and overcome it? How do I get my confidence back?