Bill,
I would highly recommend you see a neuromuscular specialist. Unfortunately, these neurologists are few and far between, and normally only exist in a university setting. In Denver, there is Dianna Quan at University of Colorado. Start there. If you are up for a trip, then I would recommend an MD in Phoenix who is an expert in MMN/ALS/Neuromuscular, or a host of other docs around the country. Mayo is also great but might take a while to get into. I hate to say this but typically MMN doesn't affect the neck or speech. You absolutely need to be worked up by a specialist soon. The good news is if it truly is MMN there is treatment for it, although it is a complex intravenous treatment, the effects are immediate. But you really should be seen to get a definitive dx.
Hope you're doing well.