How are you feeling now, and how well does your brain recover from these things? I always wonder whether these kind of things have some lasting effect on, say, your ability to focus.
With regards to focus: I've struggled with that for my entire life, starting long before I ever took a drink or anything harder. Perhaps unsurprisingly, bipolar (which I 100% am) and ADHD (~95% sure; just not medicating for it b/c, y'know, "fun" drugs are a problem) are very common dual-diagnoses with substance disorders.
So it's not so much that the substance abuse made me less able to focus; it's more that I've _always_ struggled with slowing down and staying put. Alcohol and other downers were always a form of self-medication.