Given the fact that he had a TIA you probably have cerebrovascular disease, which in many circles is equivalent to having coronary artery disease. For this reason, he continued to have chest pressure or chest pain, then test that would be indicated will be a left heart catheterization. You mention that you have irregular fast heart rate: You have atrial fibrillation as far as you know? Because atrial fibrillation can cause people to have weakness and fatigue. The sotalol and other beta blockers can cause people to have weakness, but not to the point of being unable to carry on activities of daily living. She probably had her thyroid checked if you in fact have atrial fibrillation and panic attacks as the two are often linked.
I now take it PRN if I know there's a fibrillation going on. I've saved myself a trip to the hospital twice so far because it's worked.
You should ask your doctor or pharmacist about side effects...and remember that most people don't get side effects with medication (they list about every symptom one can think of) or if you do, your body will probably adjust in time so the side effects go away.
Good luck!