(((Liese))) I'm sorry. It would be hard for me to hear those words from my T too. From the outside, it might sound different from being on the inside.
Unless you ask him about it, you won't know what he really meant. It's possible he HAS had dangerous clients before or is afraid based on things he has heard colleagues experience. Or maybe he assumes that is a normal consideration to have in his line of work and it didn't occur to him that you wouldn't worry that he was feeling that way. From the outside, I took it as reassuring that even though he had this boundary crossed from his point of view, he doesn't view you as a dangerous person, despite whatever feelings it brought up for him. Again, without asking him, you aren't going to know.
I've gotten much better recently at simply asking T what he means about things that upset/freak me out or else telling him what I project when I know it's probably way off base. It's really helped me not get stuck on certain exchanges, being in pain and fear about them for extended periods. Sometimes it's really painful to share those projections and terrifying to ask what he means about something. One time, what he meant was actually what I feared, but in talking about it, it ended up not being such a big deal, because I could understand where he was coming from as well.
Anyway, if you are continuing to work with your T, I would recommend just asking him about any and all questions that are still festering. One time, several months later, I went through step-by-step every question I had about the rupture we had when T changed his mind about sitting together for a while. It was scary, but the rupture finally felt resolved by doing so and his willingness to answer the process we had gone through from his end.
I'm sorry you're going through such a hard time, but glad you're still getting support from other Ts and here.