I must be doing something wrong when I work out?

Sounds like you have had alot of health issues. I would check with your doctor before you start anything serious. But your not going to see any results with 5 lb. weights. You've already maxed out on 5 lbs. If your looking to build muscle, then look into getting a gym membership. Building muscle requires you to lift as much weight as your body let you. Also having a high protein diet is key. Eating protein right after you work out helps build muscles (protein shake). Hope this helps