I go back and forth about how I would feel in your situation. I have been in some really tough spots, but not once has a T threatened to take away support when I clearly had too little. The reality of life is that we can't always afford the healthcare we need. I don't think there should be a punishment for it. If you are up for it, I would try to find another T who is willing to help you find other ways to manage things. Even if you could find a sliding-scale program that was willing to bill, I doubt they would be worth it in terms of treatment quality. Short of needing emergency inpatient treatment, I can't see the benefit of threatening this. If it's a hollow threat to kind of "scare" you into balance, it's a pretty ****** move.
I can understand the liability he may be facing if he continues to see you decompensate and does nothing, but I also believe strongly that a person has the right to choose their own care. I don't think there should ever be a time when anyone is forced into treatment they don't want (and yes, in my belief that also includes suicidal patients). That's not to say I won't try to talk anyone out of ending their own life, but ultimately, I think it's up to that person... (if you were to involve others, then I would object, but if you are only physically impacting your own continued existence, it's all up to you). But I digress...
I think if you are worried about T's ultimatum, it's time to look elsewhere. If he refuses to see how this is not financially feasable for you, then he's probably missing other things too...
Good luck with it all.