Symptoms returned ... but different

I was treated for carpal tunnel at Canterbury last summer, by injection in each wrist. The improvement was rapid - the symptoms disappeared completely - and lasted until a month ago. I helped a friend with a day's gardening which included a stint of moving grow bags full of damp compost. I lifted them by gripping the edges, which had begun to cause me discomfort in my left hand before I stopped. Since then, pain in my left hand has woken me most mornings at between 4.00 and 4.30 am. A single ibuprofen seems to give some relief. Unlike my earlier symptoms, I am now affected on the left only; the pain is likely to visit me several times during a day; the numbness is felt in all digits, including the thumb; there is slight swelling associated with an episode, to judge by the tightness of my wedding ring; sometimes I have a sensation like a series of very slight electric shocks in the hand. All of which leads me to wonder whether this is in fact a 'carpal tunnel' issue: might it instead be a consequence of the damage which I did forty years ago, when I allowed an undiagnosed break in the middle metatarsal(?) to mend un-set. Am I a candidate for a carpal tunnel clinic consultation or should I go to my GP and ask to be referred elsewhere?