The people who walked away taught you exactly what you want the next ones to do differently.

Being left teaches something you would never have gone looking for, which is the shape of what you actually need from people. The knowledge arrives in the worst possible packaging. It does not make the leaving fair or deserved, and it does not mean it happened for a reason; it means you know more now than you did.

Write down two things you want to be different next time, phrased as what you want rather than what you dread. Keep it to behavior you could notice early. Then let people show you across months instead of deciding about them in a week.