I had a weird feeling while shopping today, it was like i might have a heart attack ,it wasnt tightning of the chest ,but a very big flutter ,normally i breathe through it if i can,but today was massive unlike the others i have felt. I am on tablets for pains for firomyalgia i need to add,along with this i have flu symtoms and blocked nose after having the flu jab in december,i also have hissing on anf off in my head.