Originally Posted by
Gracegrows 
I guess I'd also really like to hear from people about the differences between substance abuse and alcoholism and anyone who experiences the former without necessarily being addicted.
My drinking habits were very similar to how you describe yours, and I wrestled with the same questions you're seeking. There's a lot of names like periodic alcoholic, problem drinker, etc, etc. I decided whatever description fits me matters a lot less than my realization that alcohol was less important to me than what it had cost me (dignity, the woman I love dearly, her daughters I also love dearly, friends, DUI, etc).
I quit at roughly your age for 5 years, then foolishly drank for the last 16 years.