Have you tried a chiropractor? In Feb of this year I was rushed to the ER two times with chest pains, backaches, trouble breathing, racing pulse and heart rate....all of the heart attack symptoms.
The Drs. and the cardiologist couldn't find anything wrong...even a stress test turned out uneventful. The cardio Dr said my eart is perfect. My primary Dr had tried different meds...nothing helped.
I didn't know where to turn...then I decided to go to a chiropactor, and after a couple of visits all the symptoms had disappeared! My back was so out of alinement, and that causes many many problems. So if your Dr doesn't help, try a chiropractor....the results, in my case, can be amazing!
I am 52, with family history of heart problems...it is a very scarey thing to go through....I'm lucky that I was helped so fast...
Good luck and I hope you are feeling better soon!
It's impossible to determine whether this is related to the mono or something completely different over the internet.
However, any time you have chest pain with difficulty breathing, you definitely need to get it checked out IMMEDIATELY!! If you can't get in to see your primary care doctor TODAY, then go to the nearest ER! It might be nothing, but with chest pain, always err on the side of caution.
I hope you feel better soon!