This being your 3rd pregnancy you may need to buy a belly sling to pull you belly up some because your muscles and not as strong it will help ease the pain.
I know exactly how u feel ive been having the same problem and got told multiple times that its round ligament. Im 27 weeks, ive been having this problem EVERYDAY since 13 weeks. I have a 9yr old and 5 yr so this is baby number 3 for me too. I know your pains its really bad i thought i was the only one. I take a warm bath, i have a maternity belt that helps here and there. I honestly think theres no way to get rid of the pain i tried everything from cold rags, to heating pads. I hope u find some relief i gave up at this point idk what else to do i just deal with the pain..it even hurts to lift my leg to put on leggings! No doctor understands what im trying tell them.