The simple answer is to know that “loss of control” in regards to drug and alcohol use is a myth. Individuals take drugs and drink alcohol to the exact levels and in the exact amounts they want to take them (even though they may feel out of control when doing it). Research has proven this over and over for decades. The Freedom Model for Addictions reviews and lays out this research for readers like you. The following paragraph comes from Chapter 3 where some of this research is introduced:

“First, recovery ideology says that addiction includes a “loss of control” whereby addicts will not be able to stop drinking or drugging once they start. Several laboratory experiments over the past 50 years have shown this to be false. None of these studies have confirmed the existence of such a weakness in people labeled as addicts or alcoholics. What they’ve shown is that, when those diagnosed to be “addicted” are given a substance without their knowledge, they don’t seek out and keep taking more of it. These studies have also shown that self-described addicts will moderate and save up several doses for a binge when the supply of a substance is tightly controlled and that, when faced with offers of money or more substance, most addicts have their price and will turn down the next dose they’re offered in favor of the other reward. What’s more, data shows that at least half of former alcoholics become moderate drinkers. All these facts demonstrate that cognition and choice are the factors ruling addicts’ behavior rather than a mysterious loss of control, phenomenon of craving, or weakness of will.”