Before we were married, I told her that I had a problem with alcohol and that I thought I had to quit drinking altogether. She said she didn't think I had to do that, I just had to stop after having two drinks. That was over 20 years ago, and at the time my drinking was limited to weekends. I didn't classify myself as an alcoholic at that time, but I knew I was different than my friends. I could not stop after two drinks. About 2 years after we married, I was able to quit, without recovery, for about a year. Then one day, she suggested that I had gotten over my drinking problem, and she thought I could handle stopping at one drink. I knew better, but tried it, and once I had my first drink, I couldn't stop drinking until I got drunk. And then couldn't go back to not taking the first drink.
We have had marital problems almost right from the start. The problems are more severe now than they ever have been, but they were also very severe for the 3-5 years before I recovered. The nature of her attacks on me are much more aggressive since recovery though.
I'm not sure I understand what you are asking when you ask "what was the reason for the problem?" Are you referring to my alcoholism or the marriage? If you are referring to alcoholism, I think it is too complex of an issue to handle in this thread, but I'll try to give a brief explanation as I understand it. Alcoholism is a combination of a genetic predisposition that makes it virtually impossible for the alcoholic to stop once they start, and an obsession to take the first drink. The genetic disposition is no different than a disease, but the obsession to take the first drink is a combination of many things. I could blame the obsession on these things, but the bottom line is that I was not putting God in charge of ALL my life. Even though I was a Christian for virtually all of my life, I did not turn all of my will and life over to him. I still don't, but I have a completely different outlook on life, and handle things completely different than I did before I recovered.