I'm thankful you stopped drinking; you are a better person for it, and in the end alcohol might have destroyed you, or at least shortened your life. God loves you (even if you don't believe it right now) and He doesn't want you to do anything that will damage you.
Yes, sometimes we can exercise self-discipline and change our lives in some ways. But where did your self-discipline come from? The answer is, it came from God. God made you the person you are, and whatever good you have in you came from Him. The Bible says, "Every good and perfect gift is from above, coming down from the Father" (James 1:17). Why not thank Him for giving you the discipline you needed to stop this destructive habit?
But let me point out two other facts. First, some day you may well face something you can't change by yourself–a serious illness, a broken relationship, an unexpected setback in your career, a difficult decision. What will you do then? You need God for those hard times.
Second, some day you will face eternity–and it would be tragic for you to try to face it alone and without God. But it doesn't need to be that way. Don't let pride, or anything else keep you from Christ. He alone is your hope–for this life and the next.