Family challenges

My mom is a narcissist. Over the past years I have distanced myself from her. But many times I miss her and also feel guilty of not being there for her during her old age. My husband and therapist fear she will hurt me mentally if I go back close to her. It is hard for me to not to give her benefit of doubt. I don’t know if I should believe the clinical diagnosis. Because of being so cautious, now everything she says triggers me and my amygdala gets fired, it’s like my brain is focusing on things to as certain she is a narcissist