The muscle spasm was probably just that. The other symptoms may have been anxiety if you are prone to anxiety (I am guessing you are).
Sometimes irritated glands in themselves can produce mucus (probably what you felt that the water got rid of). I still have my tonsils and if they get irritated, I will have occasional mucus in my throat.
Please try to calm down. If you had torn anything in your throat, you would likely have had pain that sent you to the emergency room right after it happened and possible bleeding.
I have to say that when I did my original neck and shoulder injury, it was the first time for me as well. I got in the next day, so I did not have a build-up of discomforts like you are having.
Take a deep breath, keep sipping your water and try not to turn your head too far.
Let me know how everything goes!