I'm a 53 year-old male and do regular Cardio Exercise every week ...

I'm a 53 year-old male and do regular Cardio Exercise every week and have for 31 years. A cardiologist put me on Toprol XL 25 MG on November 22nd. The Doctor prescribed it because I add heart irregularities and palpitations which resulted in me going to the hospital as I didn't know what was happening and never had heart palpitations before in my life. I went to the emergency room and they got me stabilized but brought in cardiologist. My heart returned to normal function in a few hours and was result of taking a decongestant as well as Lisinopril 5 MG. I had just started these drugs and had been on them for three days when the heart palpitation instance happened. The decongestant is ... I had done a two hour hard workout at the gym which I do regularly 3 times per week and then the heart irregularities started on day 3 of taking the two drugs. A cardiologists now has stuck me on this Toprol 25 MG after that day because it helps with irregular heart beat plus my blood pressure was a bit high around 140/90. I immediately started noticing side effects from the Toprol 25 MG but stayed on it plus the Lisinopril 5 MG and 325 MG Aspirin for about 12 days at that dose. I started side effects like tremors, tiredness, constipation, strange dreams, anxiousness, impotence, and struggled to do my workouts etc. I made some lifestyle changes like eliminating caffeine, alcohol, etc and that plus the medicine reduced my blood pressure below 120/80 a bit. I stopped the Lisinopril on December 3rd and my blood pressure is still normal and reduced the Toprol to 12.5 MG at the same time. I did research and the doctor also thinks the irregularity was due to the Decongestant and Lisinopril I had taken for 3 days as both have heart irregularity and palpitations as a side effect. I decided I want to get off the Toprol XL altogether and let my body go back to normal functioning. All my problems were brought once I started taking medicine and the only real problem I have is high blood pressure which I can control now with life style changes and natural supplements. I called the cardiologist's nurse and she said not to do anything until I see the doctor on December 18th. I had already decided to cut the dose in half to 12.5 MG on December 3rd anyway and the side effects got better, but then I had instance the other night after taking a spin class at the gym whereby my heart beat stayed up around 82 bpm for several hours and normally is 59 pbm. I also felt anxious and couldn't get settled to sleep real well. I read on the warning label that your not supposed to work out during the process of reducing the dosage so I guess I will have to stop working out until I'm off this stuff. I have been an exercise person for 31 years doing at least 5 hours of Cardio Exercise per week and then racing bicycles in the summer months doing 10-12 hours of Cardio Exercise. I really want off this drug so I reduced to 6.25 MG today and will stop working out I guess until I'm off. I feel a little shaky and feel sort of like I could faint if I did to much exertion since reducing to 6.25 MG today. I was wondering how long it take to get off this Toprol since I was only on it for 12 days at the 25 MG dosage and should I keep cutting the dosage and go down to 3.12 MG after a few more days and then eventually off after a few days at 3.12 MG? Then how long once I'm off should I wait to return to my rigorous exercise routine?