Could my neck pain and speech difficulty be due to a stroke, nerve damage, brain damage, crystal meth smoking withdrawals, or medication?

Neck pain & speech: Please see a doctor ASAP if you have not seen one. Any of the causes you mention are possibilities and if something is brewing, e.g., a stroke, you need medical attention at once. Please get support for the drug use you are freeing yourself from, your doctor and a 12 step group. Peace and good health.

The answer is YES.: Neck pain is common with many causes. The fact that you are 54 and use crystal methamphetamine & tobacco is of concern. You haven't told us what type of speech problems you are having. However, I would definitely recommend a prompt medical assessment.