toprol side effect

i am a 33 year old female who have had 3 open heart surgeries, two of them are for mitral vavle replacements and the other is aortia. all the years of taking different medications i have had some side effects from some of them. i'v started taking toprol xl in sep 2005, and i have had a lot of hair loss and rapid weight gain. some swelling in hands and feet, when standing and even sitting at long periods of time. i'm always tired,sleepy, and have no energy at all. i don't even have energy to do activities with my kids.