I can sympathise with the OP's distrust of GPs. I have the same. In the past, a lazy GP diagnosed me as asthmatic, consigning me to 5 years on inhalers. 5 years on, and in a new job, I needed to be fitted for a respirator at Porton Down. I thought I'd better mention the diagnosis to the camp doctor before they put me in the gas chamber for fitment tests. Some lung tests, and no, I was not asthmatic, and never was asthmatic. Overuse of ventolin is associated with heart damage. Thanks docs. But to the GP, someone coming in complaining of wheezing in bed, it was easier to follow the guidelines and write a script rather than consider the possibility of ordering igE tests, to check this wasn't in fact an allergic reaction.
More seriously, I believe a GP's failure to recognise symptoms resulted in my mother being rendered a paraplegic (wrongly suspecting a sore back with accompanying fever in an immunocompromised patient, was orthopedic, and prescribing oral morphine for pain relief (the pain was actually due to an infection near the spinal cord. Morphine suppresses the immune response, and was the final coup de grace).
When my diabetes symptoms first presented in April, a locum GP didn't bother to measure my BP, saying I could do it myself. At first she suggested I had an STD because my wife was Thai (!). Then she put me on a 2 week cancer diagnosis pathway for bladder or prostate cancer. I was getting urthroscopy appointments within 24 hours without even a PSA test, or simple urinary haem test (a dipstick test the GP can perform). I had a blazing argument with the Consultant why I was reluctant for an urethroscopy in the absence of supporting evidence (he called me "non-compliant"). Although a urethroscopy is routine, it is a hospital procedure where there is anaesthetic, and there is a risk of scarring and the need for a urinary catheter. No thanks.
But I don't have a STD, not cancer, but I have diabetes, which felt like a bit of a relief. The crappy treatment (thus far) is of no surprise to my, given my own personal experience, plus experience of caring for my paraplegic mother and late father (who had Alzheimers) since 2017. Maybe the stress caused my diabetes, or maybe it was inevitable.
But regarding pain in the limbs and diabetes, there is a possibility of conformational bias, ie that all your symptoms are the result of diabetes. Lots of things can cause the foot pain you describe, nt least the gout you've had before. People who get gout (a build up of uric acid crystals in synovial flud) generally have it for life; my dad used to get it, not all the time, but every now and then. There is another condition called Morton's Neuroma, which is basically a build up of fibres in the fleshy part of the foot (the ball of the feet), causing inflammation of nerves, and pain, presenting itself as numbness in the two biggest toes. This often happens in people with flat feet or poorly fitting shoes (treatment is basically massage of the foot, there is surgery, but you can end up with a numb foot).
Its easier for the GP to say you have neuropathy than to order the tests to investigate alternatives, because for the former, there is nothing really the NHS can do to treat it. Going back to my mother; in Europe, most spinal injury patients are initially given a diagnosis of an incomplete spinal cord injury. In the UK, its completely the opposite, which most initially diagnosed as complete, and then only much later, receiving a revised diagnosis. The reason is you can't treat a complete spinal cord injury, just teach patients to live with it. But if incomplete, then there are treatment options, but time is of the essence. But these are expensive treatments.....
Go back to your GP and ask about the gout. Though gout is also a complication of diabetes. Untreated gout can lead to orthopedic problems.