Really? You promise you will be here Monday or Tuesday at the latest? Well, if things get a little hairy on Tuesday, can you pinkie-promise to be here on Wednesday?
Do YOURSELF a favor - throw the shit out RIGHT NOW. Did you read what you wrote? Your friend's dad just dealt with cancer. CANCER. There is no messing around. The shit you put in your lip is death. Man up, throw it out and embrace the suck, friend. I guarantee you, there is no better minute to quit than right now. The sooner you make the commitment, the better.
Jump in with both feet and kill your addition to the can. You can do it and there are HUNDREDS of brothers and sisters here to help. Waiting until after this weekend will only increase your desire to keep putting shit in your mouth.