I totally know the answer to this one. I've had a lot of massage, dr's appts, chiropractic care, etc. for this one. But nothing helped me like the sacro wedgy. A massage therapist sent me to a massage store on congress for mine 15 years ago, but I've now notice you can get one for double what I paid off Amazon! There's a male and female version and when you see it, it's hard to believe that it works, but it really does. The key is to find the right chair & placement for it when you are at rest!
I have dealt with sciatica in the past. After countless trips to the chiropractor, acupuncturist, massage therapist, pain management doctor, and using a standing ergonomic desk, I have been able to live pain-free by diligently doing the exercises recommended for sciatica, specifically the figure 4 stretch for the piriformis. I do this stretch every day. It's amazing! I hope you find your relief soon.