Following on from what
@joeylittle said, and I could be waaaay off, but is it possible that part of you, maybe just a tiny part, was actually hoping for this kind of response?
Sometimes when I'm talking to my T about my self-harm, I try and give him the most watered-down version possible. But other times, when I kinda know it's out of control, I'll give him every last nasty detail, straight up. Part of my head knows that if I do that, he's gonna be p!ssed at me that I'm doing it again and make threats about hospitalisation etc. But it also means he'll take action, and help me stop, because it's serious.
You know the law. And you've been incredibly frank about the issue: "this is neglect" rather than statements like "I don't use much/use it all the time/use enough that it impairs my thinking..."
Maybe (maybe? Possibly? Possibly not...) somewhere in your head you actually get that this is a problem for you and you'd like some help. P!ssed off about the threat? Sure.
But if there's a small part of your head that was actually hoping for the kind of reaction you're getting to validate a concern you might have that you may need help with this, that's not just okay, that's good. It is a problem. Your T is bang-on telling you to "fix this pronto". So do that. You've got your T's support to deal with this issue if that's what you'd like...