I don't think anybody "disbelieves" you. I personally think it's weird that a psychiatrist would diagnose somebody they don't know. Usually they like to get "both sides of the story" before making a diagnosis, if that makes sense. So, it's unusual for a doctor to make a diagnosis about someone they haven't talked to. But I do believe you when you say he said that. It's just that technically speaking, one could lie to a doctor (or even misinterpret someone's actions), and if the doctor doesn't hear the other person's side of the story, then the doctor's judgment could be biased/wrong. I'm not saying you lied, though. I'm confident you told the truth. But I'm just speaking in general terms about why doctors don't like to diagnose before they meet somebody. It's just standard practice to meet the other person before diagnosing; that's all. I think that's what people are getting at.

But regardless, it sounds like he was watching out for your personal safety, which is awesome. It does sound like your ex is toxic, though, and I agree with your doctor that staying away from toxic people is a good thing!