Is weakness, tingling and pain in left arm normal during and after heartburn? Heartburn isn't frequent, but arm pain, weakness and tingling is new.

Focal Weakness. Focal weakness and pain in your arm cannot be related to heartburn. It most likely is resulting from your neck and possibly the herniated disk, but I really would need more information to provide a more definitive answer.
Pinched Nerve. Sounds like you have a pinched nerve in your neck. I would suggest seeing a pain/spine specialist to evaluate you further to evaluate what level and what can be done to treat you. There are interventional treatments besides medications and surgeries that might reduce or eliminate the pain altogether.