Help please??

I've been dating my boyfriend for about a month, and he has an extremely large penis. I'm a very tiny girl, and not even close to being a virgin, but everytime we have sex, without fail, I bleed. It doesn't matter how much foreplay/warmed up I get, or even how slow or not deep he goes, I'll end up bleeding. I've never had this issue before, but I've never been with someone as large as him. He's so sweet and very patient and gentle, but I would really like to figure this thing out. Does anyone have any ideas, advice, or things to try?