What was my mistake?

I have been asking myself this question for the past 2 days. But not yet been able to find an answer to it. What have I done wrong? What was my mistake? How have I hurt you? Just want to know only that much, nothing else. I don't want you to change whatever decision you have taken. You decided to walk in one day and now you decide to walk off. Fine, I have no issues with it. I have learnt to live with such situations in life. I will just go back to my life the way it was 8 months ago. I can live my life on my own. But I want to know where I went wrong this time....