'Healing' in current youth and wellness usage means actively working on emotional recovery from past hurt — therapy, journaling, setting boundaries, processing trauma. 'I'm healing' or 'I'm in my healing era' is a self-aware way of saying 'I'm taking care of my mental health'. If your teen uses the word, they are engaging with modern conversations about mental wellbeing. Positive sign; only worth concern if it suggests they are dealing with something heavy that they could use help with.