Getting high/drunk is your go-to way of coping with stress. At the moment your brain is telling you to calm down in the best way it knows how. We call it your AV or Addict/Alcoholic Voice. It comes from a very primitive part of your brain.
You need to be aware of AV, and know that it will pop up unexpectedly, and at times you can predict very well. I found that 5 deep conscious breaths were enough to calm me down and de-stress. Some people eat right away, especially carbs, others go for a run. Find out how to divert cravings with emergency measures so that periods of stress no longer mean relapse.