back pain in doggy

my boyfriend and i recently started having sex and the first time we did doggy was amazing. we have a significant height difference and that seems to be the easiest position for us so that’s what we’ve been doing every time. the last couple times however i’ve been having extreme lower back pain, making the sex less enjoyable and i almost can’t stay up. i’m not sure if it’s just a personal back problem, if it could be because he’s kind of rough, or something else. does anyone else have this issue?