My T has reacted very similarly in the moment when I have mentioned sui thoughts/feeling like I can't go one more day/feeling unsafe with myself/etc.

I remember thinking - wow, that was a non-reaction. Not that I mentioned those things for attention or anything, but I guess I thought she might 'care' more.

What I have found, though, as time has passed is that there was way more going on behind the scenes in her brain about all that I was saying that she let show on the outside. I don't know the reason why, exactly, but she has said several things over the past months that let me know that she was well aware of how close to the edge I was and that we need to work now (while things are better) on ways to cope, etc. if I get to that place again.

All that to say - maybe you T didn't take it lightly, but she just controlled her reaction to you for some reason. Keep talking with your T and if you feel you need immediate help because you feel unsafe, please reach out to a real live person in your life and tell them.