Welcome back LPG, sorry to hear you drank again. As far as your question of when you will learn the lesson for for good, that's really up to you. Do you foollow any sort of plan or program to address your addiction? Most of need to do something on a regular basis besides just "not drinking". It will definitely help you address your other issues if you can stay sober too, you realize how much worse drinking makes them too, which is good. Spending more time here can even work as a tool in your sobriety toolbox, and you can learn about other more formal plans too.
Use this as a learning experience and move forward.