Four years ago, I was a healthy individual. Long story short, one day during kickboxing sparring I got hit in the head in a strange way and thought it was a light concussion. Overtime (3- four months) I continued with other sports and it turned out I somehow injured my neck (whiplash or something). My neck became very tight and ears were sensitive to high pitched sound. It was also difficult to turn the head.
Four years later, my neck still gets occasionally tight but I can do weight lifting and non-contact sports. The only issue is that I cannot "smash" anything. I cannot hit the heavy bags even moderately or I cannot run, because it jolts something in the neck and the neck becomes uncomfortable and tight the day after. I cannot even clap too hard.
I also cannot look down for too long such as playing piano or reading a book.
Does anyone have any advice? I want to be able to at least get back to hitting heavy bags, running, and reading normally.
MRIs show nothing and the doctors don't know what is wrong