cocain and smoke cigarettes also drink beer at same time

i have used cocain ,beer ,cigarettes at same tiem for 2years .WHAT IF I DONT QUIT ?WHAT WILL HAPPEN TO ME?AND AFTER I USED THOSE STUFF I DIDNT EAT FOR WHOLE DAY .WILL I GET A STOMACH SCANCER AND LUNG SCANCER ,LIVER SCANCER IF I STILL USE THEM MORE YEARS? AND WHAT IF I QUIT FROM NOW ,CAN I GET BETTER HEALTHY AND DONT GET THOSE SICKS?AND HOW CAN I QUIT THEM ?PLEASE TELL ME THE THE WAY TO QUIT THOSE POISON STUFFS