That's a lot of pacs. I would not doubt they would make you feel tired. The heart is not beating at a normal pace. It is irregular. Besides the meds I would try to work on any stomach issues you may have. Acid reflux can add to our ectopic beats. As well avoid all caffeine, cut back on sugars and carbohydrates and drink lots of water and see if they lessen a bit for you. I hope they settle down. Maybe consider an ablation if some of the things I mentioned don't help.