How does conflict affect your mental health?

Depends upon: how you handle it. Humans deal with conflict all of the time. If one is assertive it can lead to a satisfactory conclusion and probably strengthen your ego. If it is handled in an unhealthy manner it is likely to lower your self-concept.

Dr Broadwell agreed

It depends: Certainly high levels of chronic conflict can have adverse effects on emotional and physical well being. For all the dilemma conflict creates, however, it is also an essential tool for promoting intimacy. In other words, not all quarrels, disagreements, and arguments are bad. It depends very much on how the conflict is managed. If handled constructively, conflict can bring people closer together.