I had 2 similar episodes about 10 years ago now (I have a heart defect from birth)
Both times were symptoms of heart attack, chest pain, weakness, heart rate, dry mouth, feint, pale etc.
Went to hospital and all the tests and injections etc.
I put it down now to panic attacks but still not sure to this day as like I say I have a heart defect so always crapping myself when I get a twinge.
Very scary
Hope you are ok mate.