This happened to me at the start of the year. Doctor was convinced it was arthritis, but after xray, it showed no arthritis. Had to see Physio, he diagnosed Femoral Acetabular Impingement. Nothing to treat it, other than co-codamol and ibuprofen. and of course, the dreaded excercises. The pain brought me to tears at night, it was worst lying down. At times, I really couldn't walk, had 2 months off work. It eventually faded, even though I didn't do the excercises physio had recommended, it was just too painful. So it was a self limiting condition, and I was so glad about that, thought I was condemned to suffer for the rest of my days(I am only 66). So take heart, it may work itself out, I hope so because it is so debilitating. It does twinge now and again, but nothing like it was initially.
Btw, my x-ray results came through the following day, I was gobsmacked!!