Gluteal Tendonopothy

Had something similar. I know yours is more hip it sounds.  Have you checked high hamstring tendinopathy.?  

Tendinopathy spelled that way btw for this.  It’s also called proximal hamstring tendinopathy.  I’ve had PT for this, and it can take a long time to work through.  Very painful.  For me it was caused by working out 6 days a week without enough rest days.  Runners tend to get it as well.   Over stretching of the high hamstring area, and deep pain.  Doc sent me to PT.  I wish you well, very nagging, deep pain.  I feel ya.  See if doc can send you to PT.   Worked wonders for me, and physical therapists give you the knowledge based tools to understand this and work through it.  Key was to keep vigilant with the home exercise as well.  Now back at gym with my gym friends and making sure I stretch  and rest in tandem. It can be worked through, time and patience helps.  Feel better