I think my boss thinks I might be in an abusive relationship

Sorry, this will be a long post, but I need some sound advice.

So, I recently (about 5 months ago) moved jobs. I work in finance and I was approached by my ex-manager who moved to a different business and had a work opportunity that would lead to a progress in my career. The job was with his old boss (they're still friends, he left the job because he reallocated), and after meeting with him, discussing the role and visiting the office, I decided to take it. When I handed in my resignation, my previous employer became verbally abusive and I went on sick leave for the remainder of my notice period. My new employer knew this, as he was informally helping me to get legal advice on how to approach it all.

I started working for the new employer and the job is quite demanding but I'm enjoying the learning. However, I think I have social anxiety (for which I'm getting treatment) and I developed anxiety since I resigned and was verbally attacked by my old boss. I feel like I'm walking on eggshells when I'm talking to colleagues and seniors, and my social anxiety means I have a fear of being embarrassed.

The thing is, I think my boss thinks I am in an unsafe environment at home. We had a wider conversation about how he likes to make employees feel respected, but sometimes when people don't get respected at home they have the same expectations at work. He made such comments to me a few times now, and then stopped and asked me for my opinion. I thought he was talking about things in general, and so I said that yes, that can logically happen if someone is not feeling respected elsewhere. He has also made a comment about domestic abuse and I later realised that he was searching my face for a reaction.

I'm actually in a very safe and respectful, loving relationship with my partner so it couldn't be further from the truth. I am just shocked by the comments and quite hurt actually.

I don't quite know how to approach this, I think it's quite inappropriate to stick your nose into your employees personal life but if he was concerned about someone's safety, I'd understand. I just don't get what made him come to that conclusion.

Any advice on how to approach this tactfully?