I am assuming you know there are no magical cures. Your determination is key. Keep trying. Here are some steps that might be helpful:
!) Decide you are going to quit and remember why. You say it is bad for your health and you need to quit in order to maybe donate your kidney. Also, we might add it is illegal and it is expensive. Remind yourself of thesE reasons over and over.
2) Find new friends. I asked that questIon for a reason. I am afraid as long as you are around it, you are going to smoke it. I know this is tough. It all depends on how bad you want to quit. At least limit your contact with these guys to what is necessary. This is probably the toughest step but the most important.
3) Find support. I am assuming you have friends or family encouraging you to quit. ask them to help you by keeping an eye on you and encourAging you daily. There are also ussuallt support groups available...even online. You might also consider counseling. It souns as if you smoke to relieve stress. Maybe a counselor could help you find good alternatives. Just a thought...
4) Find something else to occupy your time. Don't replace this Addiction with another, buT find a hobby. I am not sure what your interests are but find something to occupy your down time.
5) You might talk to your doctor or therapist about prescribed mediCation. I am reluctant to mention this but it does sound as if you are self medicating. I would only try this if all else didn't work.
I hope this was helpful. More than anything , don't give up. if you slip up don't throw in the towel. any questions. please feel free to ask.