[ZenGum]

My first reaction is of the "don't cling to your ex" variety, but consider that there are two cellar regulars who have got back with their ex and are making it work. I guess it is case by case, so I have no specific advice.
But don't screw yourself up (or down, rather) with drink and drugs. And for goodness's sake, don't call her while you are drunk at 2 am. Just don't.

Here's a suggestion: can you find time and opportunity to go hiking/camping for a week or two? Take no booze, go out alone away from everything, and have a long hard think about your life. You might find some clarity or decision. Just make sure you come back. Just an idea, I guess the weather might not be too great for it right now, though.
Good luck, I hope you find your path.