The grinding you seem to be exhibiting in your hip suggests compression of the joint. This in itself can be causing your problems. The root of the compression is what you need to address.
You say it hurts when you stretch? Given what you’ve described, I would expect that it would hurt to stretch that hip. Unfortunately, stretching is often a practice of finding where it hurts and staying there until it doesn’t.
If the hip really feels ‘sick’ as you say, then seek out a professional to help you with the issue. Just remember that the external rotators of the hip and flexors of the hip all wrap around the head of your femur and will pull the head into the acetubulum (cavity that the femur connects to the hip with) and can cause pain and aggrevation.
Try split squatting. Do a search on the exercise on the home page and compare the range of motion, right vs. left and see if you are limited at all. If there’s any major difference, then that’s probably a good place to start.
Otherwise, you’ll have to find someone who can assess you in person to figure out what’s going on.