I've had sciatica from time to time and at a couple of points, for extended periods of 3+ months where I cannot even really stand. It's a nuisance and disabling that's for sure. : ( Very sorry to hear you are having to go through this.
For the past few years, I'm having chronic psoas (on the other side) pain with some other hip & back issues. I won't get into all that.
Have you tried any myofascial release work either with a bodyworker/massage therapist or on your own with balls like soft ones (like elaine petrone) or lacrosse balls? Lacrosse ones of course are hard, but I find sometimes that is all that is gonna get in there and release it. I use them against the wall to get into that piriformis area and gluteus medius which will help (at least short term) to alleviate sciatica usually.
Have you seen a doctor or a physical therapist? Whereas most uncomplicated sciatica is a hip/glute issue, with some folks it is actually orginating from the lumbar and even sometimes the thoracic spine or it can even be uterine in nature (fibroids etc.),so it is worth it to find exactly where yours is orginating from. I don't mean to go all Dr. internets or anything and scare you, but I suppose I have had so many issues of this nature myself and I have seen so many women,especially, just go on and ignore it, that I don't want anyone else having to go through any long term pain.
For me, I actually find deadlifts (straight legged) helps, but everyone is different. I cannot do many reps of step ups or step work though. And this might sound strange, but for me, I found I was overstretching some muscles which was having the opposite effect of what my body needed. And what I mean by overstretching, is just stretching too far too fast, rather than going with the "pace" of what the muscle was naturally allowing me to do. I think that's particularly important for hamstrings. They are tricky muscles!!