Throat always feels tight (choking feeling) when singing, talking not talking etc and the intensity varies daily and has been persistent for at least a year. what could this possibly be? is it anxiety issues? it goes away with a muscle relaxer?

I think this is anxiety and tension although I have seen this as an early sign of Parkinson's disease but I don't think this is the case with you. A neurologist could evaluate & advise you but first I recommend stress management teaching by a psychologist.. A speech pathologist at your hospital may be able to coach you and help you work through your speaking issues.