To me, the ability to say no to alcohol is like a muscle; it gets stronger with use. The more you are able to say NO!, the easier it becomes the next time. You may not notice any difference at first but after a few months, if you look back, you will see a lot of gains have been made.
It is also a lot easier if you "deliver yourself from temptation" by keeping away from your past drinking places and companions and find new friends and activities. Starting an exercise and healthy-eating routine will give you positive feedback and a renewed sense of personal virtue. There is nothing like feeling a bit smug about oneself to make life a little better.