I work out 2 to 3 day a week. I still hurt.  why is that?

Depends. There may be multiple factors involved. Do you warmup/cooldown and stretch pre and post workout? Are you hydrating enough and eating properly? Are you using proper techniques if you are doing weight training? Do you have an undiagnosed medical condition? If you are working out right and eating right, you should see your primary care physician to do a work up for your fatigue.