There is good news and bad news. The bad is that you did make a mistake and he is an alcoholic-- nobody does what he does that isn't an alcoholic (and you know it). The good is you are early in the marriage and it's easy to get out if you want to get out.
One thing-- you are here because you know something is wrong and you know you made a mistake. Please, please, please keep an open mind as you read the responses to your post.
It goes from not too late to too late very, very fast. If he does not immediately admit to you and others he is an alcoholic, and he does not immediately seek a course of treatment through AA, Rehab, etc., and then fully commit to it, in my opinion the next several years of your life will be hell, and you'll never get them back.
Also, and for the love of all that is good and decent in this world, please do not bring a child into an environment with an alcoholic father. That would not be an act of love-- it would be a monumental act of selfishness and WILL NOT get him sober. My wife started drinking when our daughter was three and our daughters childhood, despite my best efforts, was nightmarish.
I'll not say more and wish you the absolute best.
Save yourself.
Cyranoak