When I was in my second year at the university my mother died in an accident. After that I found that I had too many commitments since I had to look after the house, prepare food, go to university and attend many group works, which consumed much of my time. As such, I was not able to spend enough time with my boyfriend who was also at the university. He complained that I did not care for him since often I would not go out with him because of my other commitments. Often, when we met, we would have an argument. Our relationship deteriorated due to our misunderstanding.
He had a group of friends whom he met everyday. He had one friend who was giving him wrong advice and finally he betrayed me by going out with one his friends whom I knew. I was not able to stop him but still we continued to be together and each time I asked him whether he is going out with that girl he confirmed that this is not true.
We got engaged and we married but 7 months after my marriage I realized that he was still with that girl. I spoke to his parents and then he finally broke up with that girl. But instead of feeling happy I feel frustrated and regretful over what had happened. I felt that if I had given him some more time and attention all this would not have happened. I am actually reading lots on happiness and positive thinking. Nevertheless, all these thoughts keep coming back and I am not able to concentrate on my job. Sometimes I even fought with him over this episode. I have lots of regrets over my past. I know he has changed and is sincere with me now, but I do not have peace of mind and still feel guilty. I don't know what to do.
At this stage of your life you did the best you knew how, with the understanding you had at that time. This is natural. It is completely pointless to agonize over what you should have known and what you could have done.
Give up torturing yourself with the word 'should.' You need to learn to be more forgiving of yourself for what you yourself perceived was a mistake.
I suggest you take a look at Peter Shepherd's Communication and Relationships Course, it's free to download. In particular look at the section titled 'The Self Defeating Should' on page 26.