i think most of the pain is due to the fact that your hymen hasnt been completely broken yet, and also because your stressing too much making it tense and therefore intensifying the pain.
has your boyfriend had any past sexual partners before? if he has, then it could be a problem he's had for a while. if your his first, then i suggest you both just get used to each other for a bit..its most likely due to inexperience. it will get better!
"We all take different paths in life, but no matter where we go, we take a little bit of each other everywhere."