My husband cussed out one of our customers...

Me and my husband own a little restaurant and have been working a lot lately. My husband hasn't been doing well emotionally. His dad died last month and my 16 year old step son is in a mental health hospital for self harm and suicidal thoughts. So he's been struggling. We were on a wait and this woman asked to speak to a manager. I see my husband talking to her and then yell in her face "Nobody fucking cares who you are." She threatened to call corporate and my husband said he is corporate and said he would be happy to give her his number. She said she's gonna leave us a 1 star review and was yelling and my husband said please do. I asked what that was about. Granted. She was being obnoxious. She was an "influencer" and was telling him she has been waiting for 20 minutes. We were on like a 30-40 minute wait. And that she and her family wants to be seated. He told her he isn't seating her before all the people who came. She started throwing around her number of followers and reiterating who she was and that's when my husband cussed at her. Completely obnoxious but we are a small business and I don't want my husband cussing out our business. He's going through a lot and I don't know how to talk to him about his behavior towards that customer.