I completely understand what it’s like being up in the middle of the night with pain (and here I am, answering you!). I’ve had what they thought was sciatica in the past (it turned out to be related to my disease unfortunately). BUT I learned quite a bit about sciatica at the time. Since it’s caused by an inflamed nerve, just movement alone may not help. It will not cause damage, BUT it could be exacerbating the inflammation, as if you had a bruise and kept hitting it on something. In fact, if a certain way you’re moving contributed to the problem, if perhaps you have a gait issue you’ve never noticed, then you may be making it worse (but that still won’t cause permanent damage). The type of movement that you start with, when you’re healing from sciatica, is meant to be gentle stretching, and exercises hopefully given to you by a physio who has examined how the sciatica affects you.
It’s wonderful that you’ve cut down on the painkillers, as I know that can be so tough in your body. However, so can the pain. I would recommend that, if you want to decrease painkiller use, you save it for making sure it can help you sleep at night, as that may be the most important time (I know this is difficult, as of course, we’d all rather have less pain when going through our day, but getting quality rest WILL actually lower your pain a bit, and not getting any will raise it). PP is right about TENS machines being hugely helpful for a lot of people. I also can’t recommend heating pads or a heated blanket highly enough - just something heated that you can put directly where it hurts. Some people find more comfort from ice, but for inflamed nerves, I’ve found heat much more helpful. What heated pads and a TENS machine have in common is that they can be better than painkillers because you can put them right where it hurts.
It absolutely WILL heal. You just need to combine rest with careful, targeted movement, and treatments designed specifically to bring down the inflammation, like ice and heat.
Good luck, OP. I know how painful it is, and I really hope you’re feeling much better soon.