Ask your doctor to send you to physical therapy, where they can show you how to do gentle stretches & exercises that will help. This very often helps sciatica.
I use ICE for 20 minutes every 2 hours for mine. I've had sciatica for many many years, and find this to help as it reduces inflammation & swelling as well as pain. Heat makes things worse!!!
Best of luck and I hope you're feeling better soon. Hugs, Lee