liked to think of himself as a gay version of a 33 year old frat boy
Okay, that gave me my first laugh of the day, albeit at your expense Gabenyc! But back on topic now, I just said almost the exact same thing to my xagf about her lack of empathy towards our relationship ending, and more directly to her reaction (or rather her lack of any) to it happening. Specifically like, "hey, no biggie, it was only 4 years of my life, time to go have a drink and get married and move in with another one."
All I'm able to offer advice-wise for you Gabe, is that like my A, your's was addicted before you met him, before you loved him, before you left him, and after you left him.