The one thing I know for certain is nothing is certain. Go down the back pain rabbit hole and you get a ton of conflicting info - these stretches are good, no they aren't they do more damage, do these instead. Here's the real reason for your pain, no this is the real reason, if you're over 50 do this, use this pillow, no that can hurt you, use that one, no use this chair instead... it's maddening.
I've had a bad back on and off for years. This year, the late night leg sciatica started. It's ongoing now, and it's awful - 2 hours after going to sleep I wake up with right leg pain (all throughout), and cannot get comfortable. Advil is useless. They gave me Prednisone, which works really well for me but is definitely temporary. I'm also doing daily stretches/exercises. After trying lots of different ones, I settled on McGill big 3, and added a nerve floss or whatever it's called and a figure-4 type hamstring stretch - they all "feel" good, so that's kind of my roadmap. I'm also trying to sit straighter, use my standing desk more, and use some lumbar pillows, but I am unsure about them - I feel other twinges since using them so I'm backing off them and seeing what happens.
I do feel the stretches are working somewhat, but it's a real slow go. Next appointment is Friday - next step is likely an MRI or maybe an injection.