Catchment sounds like the textbook pattern for drinking, and I read that same book
I was the same way, only a few yrs older when I started, I never drank till I was 18 yrs old. But soon as I started I was hiding it from the family and drinking 3-6 beers every friday night. Then I started wondering..."man this feels good, why only friday night?" So I started drinking Saturday nights, then Thursday nights. Few yrs down the road it turned into a fifth every night, especially at night.
Before I knew it I realized I was no going more than 2 days between drinking like that, and sadly that continued on over about a 12 yr period.
Your still young though, at 22 now is the time were you can change things and most likely have no damage to yourself/body from the drinking. Your on the right path. You see it's a problem and you want to change it. Stick with it, it'll be the best choice you ever made in your life when you look back on this.
Steve
BTW- Welcome to SR