Look at Yourself. To change relationships you need to return to a state of balance. The first step is taking responsibility for changing your own reactions, rather than focusing on your partner's weaknesses. You can't change your partner without changing yourself first. Your partner may have many difficulties that turn you off.
All relationships have problems.
However, to change your relationship, you need to be completely honest with yourself about your OWN relational triggers. For example, if someone is critical and blaming, and your response is to be critical back, the exchange could spiral off into an argument. Look at yourself here. Not at your partner. This could be the your beginning step toward self exploration and change.