Best pillow for back pain?

[AngelDelight28]

There are so many options out there. Has anyone found one that genuinely helps?
I suffer from chronic lower back and sciatic nerve pain. It's always worse in the morning and I feel like the pillows I have aren't helping (generic supermarket ones).

I find where I put the pillow to be more important than the pillow type if that makes sense. What position do you need to fall asleep in? I sleep on my side so have to have one behind my back to I can feel relax and supported from rolling backwards, then one under my top knee. Hard though as always moving around.