Pregnancy back pain

Every time I go in to the doctors and they ask if I've had any pain or whatever I'm always telling them "my lower back" and I always get the " yeah that's normal with pregnancy" but lord I don't know if this is normal back pain 😩 it's every time I lay down or sit, I get UNBEARABLE lower back pain to the point I can't move my legs nor my body and I start crying , I've never dealt with so much pain before in my life . And to get up I'll need assistance and it takes a good minute to sit up from laying down with that . Have anyone else had horrrrrrible back pain ? I've tried Tylenol, heating pad , different positions, walking , everything. I'm only 29 weeks and I've had this pain since I was about 19 weeks but it's so painful now I literally can't 😭