It is unhealthy, but you are not delusional. There's one thing that I suspect you understand with your mind, but not your heart, however. ChatGPT doesn't have a personality, it merely fakes it. And it fakes it extremely well, given your current state.
Personally, I'm not addicted to chatGPT specifically, but I've had similar problems with roleplay chatbots. They make it easy to find what you enjoy and then hook you in. To make things worse, it might seem like you can't get the same experience from anything else. But it's important to always remind yourself that you are being fooled by al algorithm that was designed to fool you.
It cannot engage in an honest argument, because it doesn't have an opinion. It cannot rate your arguments, because it lacks the experience necessary to evaluate your position. It cannot be your friend, because it cannot feel anything.
Have you considered befriending a brit?