They used you for years, took your donations, told you how much you meant to them, told you how much they cared about you. Then dumped you when they no longer deemed you useful.
In the world outside of vtubing, this behavior would be unacceptable. Instead, we gave it a cutesy name: "graduating".
Call it for what it really is. Betrayal.
Don't let them gaslight you into believing otherwise.
You didn't leave them. They left you.
You deserve so much better.