I need your expertise, is codeine a good downer for speed?

No: Unfortunately, i would not recommend this. Either way, it seems like you may need true medical care to address this issue. I would suggest discussing this issue with your medical doctor or emergency room if concerned.

Addict: The disease of addiction will lead you to despair, institutions and even death. I appreciate you taking the first step here to show the world that you have a problem. Substance abuse is very common and addiction is a disease. I would, given your attempt to reach out for help, advise going to the hospital or to your doctor's office and telling them that you cannot stop the drug use. Help will come.