I think "listening to your gut" is really about giving yourself credit for recognizing familiar negative patterns. You've heard the lies before - you saw what happened. Do you want to stick around and see if this time it will be different, or do you want to follow your gut instinct and avoid the drama?
If you start feeling the "gut instinct" in regards to someone who hasn't proven themselves untrustworthy in the past, it seems beneficial to keep in mind that, because of your former experiences with untrustworthy people, you may have a tendency to overreact.
A certain amount of paranoia is to be expected after living through trauma.
Knowing that you are probably prone to paranoia (understandably) is an important step in beginning to distinguish healthy from unhealthy behavior.
You sound like you are on the right track.
Wishing you the best.
-TC