Pressure?

I am having extreme pelvic pressure so much to where I can't walk. I called the doctor to see what she recommends I do and she said sit on a birthing ball. I did that and it just made it worse. I'm 37+6 and I just want to know if any other moms had this much pressure what did you do for it? I'm in desperate need of some relief I've even tried a maternity belt. Let's just say that was a huge failure.