Deep heat is the wrong thing to use.....so dont use that.
If you go to A&E they wont actually do anything, except maybe confirm you've slipped a disc.
BUT what they should do,, is prescribe you much stronger painkillers
Last time i slipped a disc, thats what my docs did for me, 5x stronger painkillers than you can buy over the counter
with instructions to keep moving about to stop DVT.
Ive slipped quite a few discs over the years, so when it does happen, i usually wait a week or so to see if it will go back in on its own. If it does, good
If it doesnt, then i goto an osteopath, who with heat gently massages it back in over a few sessions. If you fancy pain goto a physiotherapist who ime puts it back in using force
Plus are you sure your quacks are open on Monday......thats a BH too