I have lower back pain, been to chiropractor, doctor, and physical therapist, nothing helps?

Im female, 17 years old.

I have been having low back pain for about 6 months. I was doing crossfit for many months before i started feeling pain. It was not a sudden pain, but a gradual pain. I am currently not able to lift anything more than a 20 pounds without feeling pain. I cannot sit for longer than 30 minutes. The pain when I sit starts out feeling like tailbone pain, but spreads upwards to my lower back and hips. Recently my hips start to feel like they’re dislocating when I sit, and I have sharp pains in my groin. When I go to stand up I have immense sharp pain. Upon standing, I hear a loud popping sound from somewhere in my low back region. I can never pinpoint it. This also happens after laying down for some time. When laying, I have an uncomfortable feeling in my low back.

I have tried many different stretches, and am still doing about 6 different stretches and core exercises twice a day. I am taking ibuprofen twice a day. I Ice my back daily, but have also tried heat. I have gone to the chiropractor, doctor, and physical therapist, but no one has given me an answer, and nothing has helped. I have had a few x-rays taken, and everything seems fine