You are right to be concerned. While whatever you two squabbled about may not seem too important, you are harboring more anger than you consciously recognize. That anger has been building up since before the argument. I think you would do well to uncover what is causing you to have a growing resentment that finally boiled over. This might be just the sort of thing that couple's therapy can shed some light on.

People differ in how they respond to alcohol. You may be one of those people who just should never drink heavily. Luckily, this time, no irreparable harm was done. On a future occasion, you might not be so fortunate.

I commend you for not brushing this experience under the carpet. You're taking responsibility for what you did, and you sound committed to the idea that this kind of behavior is utterly unacceptable. I feel optimistic that you can learn and grow from this.