Hi Heather - sorry to hear that you've got sciatica pain - that can be very distressing. Getting a scan or an x-ray is a good idea, and the physio would be a good person to get you checked out. Do you have access to a multi-disciplinary team through your rheumatology dept? If you've seen the physio before then they should see you again but you might have to keep pushing and phoning to get seen quickly.
In the meantime, have you tried alternating hot and cold on your back? I use a hot water bottle for 10 minutes, followed by an ice pack for 10 minutes and then keep switching it around, and also I try to keep moving, because I'm advised that gentle movement is the best treatment. But obviously don't do too much.
Best wishes - Sylvia xx
Be kinder than is necessary because everyone you meet is fighting some kind of battle