What to do when you can’t handle the pain?

I’m not due until the end of August with my third baby. I get it. pregnancy is hard. Your body hurts. But II’ve never had THIS much back pain before. It’s unbearable. Tylenol, baths, and stretching isn’t cutting it. I’ve figured it out it hurts the worst when I sit. I’m almost in tears daily from it. . . Has anyone else dealt with this? Is there anything my doctor can prescribe be or something that’s safe for baby? I’m so tired of hearing to take Tylenol when it literally does nothing. I’m going to go crazy. I can’t function! What should I do?