Slightly different situation but I talked with my therapist about this last week. I have an exAH. My good friend is getting involved in a relationship with someone who struggles with a mental illness.
My therapist reminded me that boundaries can be flexible and change with the times. In addition my job is to "say what I mean, mean what I say and not say it mean." She also gave me a new tool when talking about hard things:
Is it kind?
Is it true?
Is it necessary? My feelings can be a reason it is necessary.