There is such thing as too big

So I dated this guy when I was 16 and we broke up and have always stayed in contact. I’m now 20 and we have recently started hooking up. I’m having a really hard time getting into it because it hurts so bad. Every time we have sex I rip really bad down there and it will be extremely painful the rest of the time and we just have to stop. I have never really had this issue before other than I am super sensitive down there already. He is just really big in all of the ways so it’s super painful. I am completely wet enough (tmi I’m sorry) and very sexually attracted to him but it is just too painful and I’m so embarrassed that I just can’t hang with it. Has anyone else had this problem and does it ever get better? Also I really have a hard time having an orgasm just from sex unless I’m on top but I don’t want to have to feel that way because I want to be able to do other things and feel pleasure. I just feel like something wrong with my body because I want sex a lot but when it comes time it just doesn’t feel as pleasurable unless we’re doing other things. Please help!