Most Helpful Guy
The break up must of really stung. But right now that's not your responsibility since not only aren't y'all together, but his actions are the primary reason you two aren't together.
Most Helpful Girl
My boyfriend and I broke up for 2 months back in 2013. It was due to one of his friends telling him that I said some horrible things about him behind his back (this wasn't true)... I was his his most trusted friend and girlfriend, he has told me stuff that he has never told anyone else.
He ended up turning to drinking and drugs, not all the time but he has admitted he went to college high as he was so upset about the break up but he needed to face the world but couldn't do it sober.
I turned to drinking, I remember it being my only escape. Everywhere I went reminded me of him and I was depressed 24/7. But I didn't drink all the time, only on weekends.
With the stuff my boyfriend has told me, he felt like he had no-one he could trust in the world, he felt betrayed... hence why your ex might have turned to drinking but the difference is he brought this on himself for cheating on you.