Imagine a ladder that you are trying to climb to reach your goal of stopping over drinking (or any goal for that matter).
At the ground level we begin with "I can't"because we have yet to do so and we are great at living in our pastto find our beliefs. In this stage the idea seems impossible and that's ok. We need to first acknowledge there is a problem with a possible solution.
Next, we move to "I Could". Perhaps you are looking for evidence outside of yourself to see if it is at least possible to make a change. You might say, "If Stephanie can do it, so can I". You are now starting to shift that you could possibly make a change.
"I will" is so empowering. You are now making plans to apply all that you have learned and actually put it into action. You are making progress. You are cutting back on your drinking and finding success.
"I am" is when you are cutting back on your drinking more than the days you are drinking. You might have taken a 30 day break and seen a HUGE transformation. You are now in belief that you are the person who doesn't over drink.
Each step is necessary.
The sooner you believe "I am" the better you will be at sticking with the goal.