I went to the emergency room a week ago i have cellulitis the doc gave me a shot of penicillin and cephalexin 500 mg for ten days i also been fighting a meth addiction i don't use needles i smoke it can this stop me from getting better i feel worse?

It certainly could: compromise your recovery and potentially lead to more serious conditions and eventual death. Check into a rehab facility and get off the illicit drugs.

Smoking never helps: Well with your condition, you may need to go back for a check-up. Your body has been weakened by the cigarettes and the drug use. Those antibiotics may not be enough, particularly if you're feeling bad. Patients like you can get into serious trouble with this kind of stuff, so I recommend going back today. An infectious diseases doc can help too. Hope you get help.