Thank you to all the lovely people here! You're all incredible.
I've taken LuckyJim's advice and got a bit more stern with my GP and it seems to have worked! I'm now allowed to take a Longtec 40mg tonight and again in the morning if needed, plus the GP says he'll ring again tomorrow...result!!
Now this is where I got confused (it doesn't take much); he said that he had "no idea" that I had been told to come straight off all pain meds, but thought I had to wean/taper off (still no clue as to what might it be replaced with); which is weird as I've looked at my care record online, which clearly states that he took me off them in the first place!
Then he said that my recent MRI showed 'changes' but wouldn't tell me over the phone, and this is where I became totally confused, he mentioned tethering....
What on earth is tethering?
But at least the GP called today and he's also going to call me again tomorrow lunchtime to see how it's all going.
Thank you so much everyone, you've all been amazing.