Sitting at work gave me sciatica. It's likely sitting to sleep that is causing yours. I quit that work and 6 weeks of therapeutic massage cured my sciatica over a decade ago. Dunno if that will work for you, but it's hard to not recommend massage as beneficial to your mental state.
Have you tried inversion therapy? Hanging upside down completely stretches out the compressed joints that likely are at least contributing to your disease. A couple hundred bucks for a set of boots with hooks and a rack to hang from can be a valuable means of altering your condition for the better. The racks swivel, which makes getting on and off possible. If you are handy, or have people that are, making the boots and rack doesn't seem hard to do, if money is a hard limit.
I hope you can win free from your agony my friend.
I'll definitely check into inversion and massage. inversion may replace the pool, which I havent used in over a month
i do need to lay down for a couppla hours each day, even if it's just to get out of a constant 24 hour vertical posture
thanks for suppport, buddy, it makes things better!