After a couple of weeks of taking a step outside of the relationship, its time for some soul searching and honesty with yourself. Actually writing this down on paper is a very good way of doing this. Write down all the positives and all the negatives of your relationship with the person in question. It is important that you are absolutely 100% honest with yourself. Try and be as objective as possible and truly analyse the relationship.
# What was the cause of the breakdown in the relationship?
# What were the arguments about?
# Do I want to mend this relationship for the right reasons?
Do not try and portion blame for individual things, this is counter productive and not the idea of this exercise. To mend a relationship you must be 100% sure of your motives and the reasons behind them.