I go to my OB tomorrow, I'm 23 weeks pregnant and my sides and back start to hurt so bad that I…

I go to my OB tomorrow, I'm 23 weeks pregnant and my sides and back start to hurt so bad that I collapse, when I sleep at night I can't turn without it feeling like it's popped out of place and I literally cry so hard and scream because it hurts, when I stand to get out of bed to use the restroom my side does a popping feeling and after it pops it feels ok enough to walk to the restroom "on my right from my bedroom) and it hurts to sit. If I sleep on one side at night I wake up crying because my side feels like my muscles are tightening up. I'm so miserable at this point and I don't know what it could be.. I'm asking my OB tomorrow about it to see what he recommends me, but with my first pregnancy (my daughter) was petite and she measured 4 weeks behind on everything, she was a small baby when she was born (5 pounds) but my side was nearly not as bad as it is now. Even when I am walking randomly it will start to hurt to where I have to sit somewhere before I collapse. What do y'all think it could be?