It might just be that all the muscles of your core (hips, thighs, buttocks, lower back and abs) are all tight and in deep spasm. When they are tight they contort and this is what pulls your lower back and pelvis out of alignment and this is what causes your discomfort and sciatica. the best thing for this is inversion therapy. When inverting all of these muscles are free to stretch out and relax. As they do the knots come out of those muscles and as they are free and lose they will release their grips on your lower back, hips and pelvis and allow them to go back into alignment naturally. Once they are realigned nothing will be irritating your sciatic nerve and your pain will go away. You just have tight muscles that need to be stretched out. Stress causes this too by the way. Hope you feel better and hope this helps you.