Hi there eveningstar
Welcome to SR.
Good for you for realizing before you got married that there is a problem with your fiance's drinking.
I totally can relate to what you say about you drinking more when with your SO (significant other)...the same thing happened to me. I never really drank much before I met my AH. But it was so central in his life, and I just joined in for a while. Flash forward some years...I "woke up" to realize that he is an alcoholic...what a mess.
You should be disappointed, like you say you are. Geez, these people have really let us down, haven't they?
It is nice to meet you...and I hope you keep posting and reading!
SR has helped me so much through this tough time. So stick around!