Being big and having sex ?

I am a plus size girl and I'm a Virgin. Me and my boyfriend have been together for a year and a half now and we have been taking about having sex. But I'm scared about a couple thing. I'm scared about how to have sex while being big is it different would he even enjoy it and also since I'm big I have discoloration in between my legs and neck and armpits and the doctors say it's not bad it's just I'm big and skin rubs together but I've never told a guy about it and I'm afraid of how he would act about it and if he would still like me. Is there any advice on what I should do to ?