First of all, thank you very much for your reply.
I tried rollers before (textured rubber cylinder variation). I don’t know if it was because I didn’t use them for long enough, but I didn’t see much improvement. The package I bought also included a textured plastic rolling stick and a textured rubber ball (I guess similar to the tennis ball), which I think are designed, respectively, for the quads (and maybe chest) and trigger point, like feet or other specific body parts, but I just tried out the roller and didn’t feel better, so I returned the whole thing back to the store.
I have read that low back pain can be related to weak hamstrings, glutes and abs, so my plan is to strengthen those parts. How did you know your episode of acute low back pain had to specifically do with weak gluteus medius, did you visit a sports doctor?
I also have had chronic back pain for a while, which in my case I presume comes from too much bad sitting while gaming as a kid and had ridden bikes for a lot of time, but never with the right saddle, as my sitbone area is as picky as they come. I also have a big lordosis and just recently discovered people with such a condition may require a more specific type of seat, namely a flat one. The fit I use on my bike might also not be ideal for my body, so I want to get a bike fit on the near future, but at the moment I am stuck with other alternatives.
I will see how I go with pilates first and if I don’t see any improvements, I’ll consider trying roller stretching again.