I hope you feel better soon. These are all good suggestions. For an emergency rice bag, take a tube sock and fill it with rice, tie a knot and there you are (Janet told me about this - Thanks Janet!). For a fast hot water bottle, take an empty 2L bottle and fill it with hot (NOT boiling - just tap water hot or it will melt) water.
I would see the doctor, esp as bad as this sounds. Also try to stretch when/how you can.
Sending very gentle hugs to you.