I too have Peripheral Neuritis; so I know what you mean by pain, numbness and pins and needles. Mine was caused from a combination of injuries and excessive alcohol and drug abuse. I have now been clean sober for 22 years!
But my pins and needles and numbness and pain CAN persist. I have pretty much permanent numbness in my right thigh, I get pins and needles in my hands and feet in certain positions, and just lately, I am having pain again in my left hip. I also have the beginnings of arthritis in my back. Again, due to injuries sustained when I was younger.
The best suggestion I can make is relax! Maybe see a physio for some stretching/flexing exercises that may help, while you wait for your specialist appointment? Perhaps you could also try some meditation exercises to slow your mind down. And remember to stick to the facts; life is about what IS, not 'what if'?! It's those intrusive 'what if' thoughts that are completely unhelpful ...... especially when brought on by seeking information from 'Dr Google'! Don't worry, you're not the only one to have googled your symptoms.
I do hope that you can get some answers and relief soon.
If it helps to know, summer is better for me than winter. Winter seems to be that bit more challenging, for my particular aches and pains. ..... and it's starting to cool off now. Oh well, such is life. Thank God for electric blankets!!! At least I can walk and talk and look after myself. There's sure to be plenty more people who have it far worse.
Take care. Let us know how you go. xo