My wife and I have agreed to a 3-month trial separation. She needs space from me, as we work through this in therapy. I am willing to do it to save our marriage. I had an affair.

My concern is what happens after 3 months if she says she wants a divorce and wants to stay in the apartment? I'm concerned that by leaving now, I'm putting myself at a legal disadvantage. I want to be in a position to say "I understand that you don't want me to move home, but this is my home as much as yours, and that is now our starting point for what happens next."
Is there language we can use in an agreement ahead of time that protects me?
And does it matter legally that I had an affair? That's the reason for the trial separation. In other words, would the fact that I had an affair mean that she gets some kind of priority or advantage in terms of the property?