Dear twoboys,
(a) See you doctor ASAP.
(b) Do not take any medicines except those prescribed or advised by your GP.
(c) Do not use OTC (Over-The-Counter) painkillers as you might only use this as an excuse to yourself for not visiting your GP.
If codamol is really a mix of codeine+paracetamol, as I suspect, and that doesn't work then nothing else will, except your GP's prescription. But re your tummy, codeine can cause tummy probs., notably constipation.
(d) It does not sound alcohol-related but you are drinking too much per day - stop or limit it to 1-2 glasses per day.
Can you do this, irrespective of your pain or are you continuing your overdrinking using the pain as an excuse?
(e) Have you had a recent fall hitting your "bottom"?
Do not panic or worry - back-pain is common for various non-serious reasons, but please put your embarrasment aside and see your GP. Just arranging an appointment might relax you and help your pain.
Many of people have a low pain-thresh-hold, maybe you do.
With Sincere Best Wishes,
SIQ.