Have you been able to talk about the feelings underlying the sui thoughts?

I used to get them frequently after starting therapy. It was a young part of me experiencing immense suffering, turns out the memories were dissociated but revived in T. But after working through the underlying feelings and how the child felt all the time, I've been able to get past such thoughts and they are rarely part of my life anymore.

Maybe if you talked about the feelings instead of the sui thoughts you could continue with him until you are able to see someone else?

I'd personally would have a hard time opening up to someone who said what your T said before about not being able to see you. (Having said that, my T has said things that seemed cruel a few times over the years, but I later found they seemed to be interventions to get me unstuck or out of a pattern.)

Since you've said you have no other options in terms of a T, I wonder if getting to the root of the feelings is worth a try; a way to move forward and continue with him.