If you want to practice crab walking, you have to suffer. You should learn to slide in the straight crab step first, and then you will be very skilled. Try to shake it from side to side (remember: always lean back when practicing, preferably on the hind foot, so that the front foot is lighter and the S shape around the flat flower pile is flexible.
Practice crazily when you feel something. It is normal that the inner thigh will have severe pain when you are about to practice. That's a slight sprain of the muscles inside (just rest for a few days, I've seen it seriously. It takes a week to get out of bed after taking medicine and sticking plaster. Haha, don't be afraid, it's usually just a slight sprain, which is harmless!