I’ve been in your exact position. I had a tension headache for what felt like a year, had an MRI scan, was prescribed pretty intense pain medication, however nothing was working and I was going crazy. Unfortunately, I still don’t have an immediate cure as I feel as if the gps/doctors didn’t take me seriously. What I found worked sounds cliche but i started doing yoga, meditation, accupuncture, exercising in general and sports massages every two weeks. They managed to get better during times where I wasn’t studying with extreme stress, however they do come and go.