There is so much more than can be done at a pain clinic than your GP can offer.
Like Davey says, there are drug free interventions, acupuncture, cupping, physio. All done by NHS trained staff.
There are also injections and interventions they can do in the clinic where you might stay for an hour or so.
The thing is when you drink to kill your pain, the pain will soon become tolerant to the drink. Then you need more drink and more drink to kill it.
A pain clinic might start you with one drug, then add another and completely tailor your medication to your needs.
You can't do that with drink.
Are you in the UK Harvey, I cannot remember if you said you were or not?
My best to you
xx