I once had a month and a half sober and started drinking again because of a friends wedding. I drank another year and a half afterwards. You are not alone.
I went back to my old sponsor and things still did not mesh between us. He helped me the first couple months but a time arrived where I had to move on. By then I had my sober legs under me. Got another sponsor that did not work out either. I will be much more selective in the future!
That being said only you know yourself so I think you have to get super honest with yourself and do whatever is necessary to stay stopped. My sobriety became the most important thing I do in life. If that means meetings, steps, reading books, posting here, calling people, avoiding people or places, or anything else I will do it. My sobriety has to stay number one.
The great news is while it felt selfish to put myself first at times life has slowly changed for the much better. All the side benefits of being sober are so worth it. But I have to do this for me.