Relationships are like debit and credit. For each good deed we score points (in the mind) and for each bad on we lose points. Points are weighted by many factors. Our stage in relationship, our personal influence in relationship,nature of people involved and gravity of errors.
Now to your problem. Calculate how much you have contributed to the relationship, both actively as well as inactively. Now close your eyes and do not think anything. Listen to the answer given by your inner deep unconscious mind. Yes you got your answer.
PS : Most of the problems can be sorted out in any relationship if people are less loaded with ego. You will be surprised that people are much more forgiving to people they love because they love! But my ego and your ego has one common voice ‘Why me ?’.