Whats a normal progress of having termination in psychotherapy after having a year of therapy?

Im just asking cause my psychothearpist just told me
Last week that our last session is this week. I wasn't even told in advance that it be our last session next week.
I was told since beginning of therapy and this year that
I could go with them, because they told me they going to pirvate practice.
They even told me there superadvisor agree I should go with them and that they give me discount.

Suddnely last week was completely a flip and slap on the face. I did wondered if they made the next week session last because they got upset with the letter I wrote, from what they've said to me in the past year that was really upsetting for me.
My keyworker read it and then gave it to my psychotheaprist. So that session they brought the letter and told me "we've already spoken about this" and didn't spoke about the letter accept they did mention they didn't mean to make me feel ashamed or guitly and that was it. It was a big letter too and I put my heart and soul writting that letter. It took two days to write it with deep thought.
After session I ended up crying all the way home driving and I self harm myself more than once.

So to have this happen to me. Is really extremely upsetting