Get on your hands and knees with a hot shower on your back (make sure someone is home) the weight of the baby falls away from your body and relieves any other pain. I also liked when my bf pulled my legs away from my body. I'd hold across one side of the bed and he'd gently pull from above my knee to give a stretch.
Sounds a little like sciatic pain. My doctor keeps telling me to take Tylenol and use a heating pad. Ask your doctor for some stretches that might help it
I was the same way its cause the baby is so big