I would ged an endoscopy of the throat, it may be more serious.
As you have stated in your post,"I went to the ER 3 years ago because i felt i couldn't breath and my throat felt tight. the doctors told me i had anxiety and to to worry." I would suggest you go see an ear and throat doctor. Not all medical doctors are always going to be able to treat people in certain cases like maybe this one. And ear and throat doctor should be able to help you out and give you answers as to what could be causing the issue. My question to you is the following;
When these feelings occur are you worried about something?
When you worry does the issues get worse?
Again, I am not a doctor so I personally couldn't give you "Medical Advice" for that is not my field for expertise.
Good Luck To You,
Autumn425