Gosh, you are young to be having such difficulties.
Firstly, the leg length. It's not rocket science. Ask someone to stand behind you, place their hands on the crests of your hips. Ususually it's quite easy to see if there's a large discrepancy. Smaller amounts are more tricky. Then bend forward: does the person behind you see the leaning tower of Pisa?
Remember that hip arthritis radiates to the knee. If you are having stiff hips, then one needs to be sure that the knee pain is not pain radiating from the hip. Lying on your back, pull the knee to the chest, and then the opposite shoulder. Feel inordinately stiff and sore, especially in the groin?
I have only two real suggestions of merit. Start the lower back exercises for facet joints, you'll find them at C-H, and do them very faithfully every morning before getting out of bed.
Secondly, if you have been to a chiropractor, isn't it time? Don't expect miracles, it will take time and hard work on his/her part.
I hope this contributes.