Hi,
i'm not sure why you'd hurt so much, unless the baby's head has already moved or engaged into the pelvic cavity, putting pressure on your whole pelvis- this usually happens early with first babies- is this your first?
Maybe, if you want to have sex with your husband, grip the base of his penis with your whole hand, and hold onto it the whole time so that he only penetrates a little bit, or use a position where he doesn't penetrate as deeply-like lying your side with him behind you- like spoons.
You definately shouldn't be doing anything that puts you in enough pain to cry- pain is your body's way of telling you to stop what you are doing. Also- if you are going to soak in a tub for long period, don't have it hot-that's dangerous.
Take care of yourself-there are plenty of ways for both yourself and your husband to have sexual gratification and intimacy without penetration.
I'll bet your baby comes a little early- but it's six weeks until it's recommended to resume sex after birth, so you'll need to develop some other ways to be intimate soon anyway.
Be gentle with yourself !!