If things are that bad then get to the er. Atleast they can run some tests and hopefully get him comfortable. Having you with him is always a big help. Then you have a second persons talking and listening. I hope your situation gets better!
We are struggling to get our GP to take it seriously. I am considering going to local hospital
I would go sooner rather than later. Better safe than sorry!
You should definitely get checked out. I would start with your regular doctor or the er would be better.
We need to do medical workup to arrive at a diagnosis, including history taking, laboratory tests, x-ray, and so on.