You may need to switch to a different beta blocker . it is unfortunate but many doctors including cardiologists just do not seem to do enough for the patient with an uneasy mind . There are several beta blockers and ace inhibotors all of which are intended to do the same thing but unfortunately everybody responds differently to medications, so it becomes a trial and error process . I am currently taking a low dose of Zebeta which for me gave the fewest side effects . I tried Toprol , along with 3 or 4 others ( all made me feel terrible) before finally settling on the Xebeta which has a reputation for having the best results as far as side effects go. If one has high blood pressure , then take the Ziac which is the same as Zebeta with a diuretic to control the BP.
Keep away from thre sweets and cut caffeine as much as possible as sugar can be a reason for strange episodes from the heart muscle.
Ask your cardiologist about the Ziac and good luck.