I have been there too... one discussion that has been useful to have with my doctors is for me to tell them how I know when I need to be in the hospital and when I don't. Then your T might feel a little more comfortable with you talking about suicidal feelings because they'll have a better sense of how dangerous it is. Does that make sense? Like for me, if I have a plan and I have done something (no matter how small) to start carrying out the plan, then I have to be in the hospital. But if the plan is is my head and I haven't done anything other than think about it, I know there is time and safety for me to work with my doctor before it gets out of control.
I hope things are feeling a little more manageable now.