Sciatic pain can stem from a number of different areas. Could be due to a disc problem in the lower back or a tight piriformis (muscle in the buttocks) which could be impinging your nerve. You may need a medical professional to confirm your diagnosis. We strongly suggest that you avoid doing exercises that cause your pain such as heavy lifting. Seeing a doctor also may probably help correct your form when lifting, as this may have caused your sciatic pain.
To help relieve your pain, you may do some lower back stretches when lying down, such as knee to chest, hamstring stretch, piriformis stretch, and incorporate core muscle exercises to prevent the injury from worsening and recurring.