We all come here by various routes and yours sounds painful to boot! I'm glad that you are able to keep things straight for so long, but it's gonna take a very long TIME to help your nerves to heal.
It also sounds [and I am no doctor by any means!] as if your shoulder/arm injury is being well, ignored from what you are saying? I don't know if or what insurance you have, but if you do? Go get a second opinion and quickly...the sooner the better. ASK about the possibility of physical therapy to help you regain some use of that arm/shoulder/hand. The sooner you get that to 'work' in any fashion, the better it is for you and also to help you keep things together for the long term. An orthopedic specialist would be my own personal choice in this aspect.
I suggest that you check out the 'threads' called 'Stickies' at the top of the forum page and read and learn as much as you can about neuropathy. Understanding what all is going on with those nerves, and then, what you as a mere human, and not a doctor, can do to help you get yourself in a place to heal is key to getting some parts of your life back. Supplements can and do help, BUT, they take a very long time to work...damage done in seconds can take months or years to heal. Don't be discouraged tho. Yes, it takes time, but it's time well spent.
I am sure that others will post soon as well about their experiences. Each of us comes to this from a totally different set of circumstances but, we all learn from each other and count on most folks being totally honest and candid about their issues. Be cool about it all and you will find that you are stronger than you ever thought you could be! - j