I think that my story might be relevant. I am a full time athlete; either skiing, windsurfing, surfing, or playing tennis 4-8 hours every day. My hip started getting pretty bad about 15 years ago when I was 45, and I was told that I would eventually need a replacement. When I was in my early 50s, it was to the point where I was constantly limping, had to give up tennis and surfing, and sometimes had severe pain when I was skiing. I went to a surgeon who was one of the few doing a lot of hip arthroscopies back then, and he said that I had labral tears, and would be a good candidate since the cartilage did not look too bad yet. His best guess was that it would buy me 5-10 years before I would need a replacement. He pointed out that one of the big advantages of gaining a few years, was that there would possibly be some advances in joint replacements during that time, and he certainly was correct. I was back to skiing within a month of the surgery, but had horrible pain afterword. He said that it would improve at 3 months, and he hit it almost to the day. I would say that I got about a 60%-70% improvement for a few years; enough to help skiing and walking, but not enough to get back to tennis. By the time that I was about 6 years out, it was getting pretty bad again. I then tried an injection of my own stem cells mixed with a small amount of cortisone directly into the joint. This was a total disaster much like you described, and I was never able to walk without a cane or crutches after that. A few months later, I had my resurfacing, and things improved a lot. I am back to all of my sports 4-8 hours a day, including tennis. I still have some minor aches and twinges, but at an active 60, who doesn't. No limp, and I can do whatever I want.
One thing that you might find interesting: the first time that I visited Dr. Gross (who I, along with many, think is one of the top resurfacing surgeons), was before the stem cell injections. He said that my x-rays still did not look horrible. We talked about the possibility of sending me to someone for an open surgery to try to repair the joint. In order to know if this had any chance, he said that we really needed something better than an x-ray, and I went for a CT scan. When Dr. Gross and I looked at the CT, it was clear that my hip was shot, so he said that it was time for a resurfacing.
So there is my story, that addresses some of your concerns. My only advice after all of that, is that x-rays do not tell the whole story inside the joint. If you really want to find out if an arthroscopy will help, you need to know everything going on in there, and you need a CT scan or MRI for that. If it really is only a labral tear and some loose particles, you might have an excellent result from an arthroscopy. If you are like me and have a lot of cartilage damage and bone cysts that do not show up well on the x-rays, the arthroscopy may not do much good, and it time for a resurfacing.
Good luck.