Don't pick up the first drink, drug or other addictive behavior. The first one causes you to want more. The first one doesn't satisfy you because this is a disease of more. The first one tells your serotonin receptors that you need more to feel content. It physically causes craving. It's that first one that is the engine and that engine is what runs you down, not the caboose. Again, the addict, the thinking person that he is, wants to complicate this theory. He wants to think he can retrain his brain to use safely. He thinks he can control anything so he thinks he can exercise the same discipline to successfully use. All these traits only lead to disaster because addiction is a disease. It is beyond will power.
Do not pick up the first one. Call someone and share about your craving. Only by not giving in to your craving will the craving go away. If you give in to it, you will crave more.