I've started carvedilol to slow heart rate. My BP has always ran low which made me very tired. Today im very week. Is this normal? :

Maybe. Carvedolol is a beta-blocker. This class of BP meds traditionally cause decreased heart rate and blood pressure. It is possible that you are feeling weak & tired because of the med and lowered blood pressure. You may get used to this, or you may be extra sensitive to this particular medicine. If you keep feeling tired & weak, you may need to lower the dose or change your medicine.