Advice from a therapist…
Practice the F word.
Forgiveness.
Forgive yourself for not believing them the 1st, 2nd, or 20th time they showed you who they really were.
Forgive yourself for the times you saw the red flags as a challenge, rather than a warning sign.
And forgive yourself for not knowing what you needed to know before you learned it.
Now that you know better, you can do better.