he's too big.

My boyfriend wants to have sex like 2 times a day && I don't want to cause he's too big. Sorry, tmi. But how can I enjoy it? He goes slow & everything. The only way I found it somewhat enjoyable is if I orgasm before we have sex cause it makes it more relaxed down there. 
He's too long and too thick. I feel very tight down there. Like very tight! It's even worse when my cervix is low.