That's similar to a problem I have had over the last year or so. One bout of the pain last year took me out of serious squat and deadlift training for about 6 weeks. The most recent time, I had to back off for about two months. Both times, it was set off my heavy squatting- the first time I was box squatting with heavy band tension and kinked my back coming off the box- the second time, I stumbled gettign a max weight back into the rack.
The first time, I tried ice, contrast showers, OTC and RX anti-imflammatories, massage and chiro. This did almost nothing. However, after weeks of painful half-assed training sessions, I started daily rolling (IT, back, glutes, hamstrings) and stretching and that got me moving again. I was back to normal in a week or so.
This past time, the the rolling and stretchign didn't do it at first. I needed to totally quit squatting and pulling for a few weeks. Then, I started rolling and stretching. Then I started back very light with high-rep squats. I have been back to lifting for a couple weeks and I feel like I am almost 100%.
I think you're doing the right things, but consider the value of shutting down your squat training for a few weeks.