I did find myself thinking 'So this means I shall never sit in our therapy room again? I shall never have him sit there listening to me ever again? Is this what this means?'
Well, it is, isn't it. It does mean this.
Adjusting to information - especially when it's sudden change - takes time. You'll need to simply tell yourself this periodically. It will begin to seem more real; this is one of those things where it just takes some time for your mind to soak it in, I think.
So why hasn't he texted me to tell me what is going on now? What has changed?
He is no longer your therapist - that's what's changed. He's officially not your clinician anymore. And I believe that it is not going to help you at all to ruminate on this.
The answer is, he's not your therapist anymore.
You had an unconventionally close relationship with him - and that is causing you some confusion right now. You're reacting as if you're experiencing a sudden disconnection from an intimate friend. He wasn't that. I'm sorry that he allowed you to invest in that idea as much as he did, because what is happening right now is the reason to be careful of it.
THAT is what makes me fear that my last text to him angered him and made him think 'f*ck you'.
I doubt that. And if that would for some reason be what he's thinking? He absolutely should not see or contact you again - because that's an incredibly inappropriate/wrong/unacceptable way for a therapist to react to a client, ever.
I encourage you, as much as you can, to stop thinking about his inner life, and focus only on yours. How he might be feeling about you or thinking about you, specifically, is no longer part of your life.
When your mind starts wondering what he's doing, thinking, how this happened - just go back to the fact that it happened, it's hard, but you are adjusting to it. If you want, it could be good for you to name your feelings - as in 'I feel sad' or 'I feel angry' - and then, 'but I'm adjusting to it'. And stop there. Move on to a distraction, something that will pull as much of your attention as possible.
Hypothesizing about him any more at this point is only going to make this transition take longer, and won't help you in the long run.
I'm sorry it's hard. But he's no longer your therapist, and it's doubtful you'll hear from him again. I wish that the NHS would give you someone short-term, just to create some sort of closure-process for you. Is that an option?