How the T handles it will depend on the situation. If he thinks you could benefit from more therapy, he will probably say so. But I don't think he will twist your arm. It usually says in the informed consent form you sign at the beginning that you are free to stop therapy at any time, and I think Ts respect this and do not lean on you too hard. They know there is often a power differential in the relationship and don't want to use undue influence. Your T might be reassured if you tell him your plan for continuing to work on your issues. (But you don't have to tell him that.)

I have ended therapy with 2 different therapists. The first one, I didn't actually mean to end, I just had to cancel an appointment for some reason. She called to reschedule and I was unable to at that time, and the weeks passed and I never returned. It wasn't intentional, but it was easy. Looking back, I wish I had not done that. I wish I had known that I wasn't going to continue and had had a final session where I told her and said good-bye. Oh, well.

The other time was with the family therapist my daughter and I were seeing. I did better that time. My daughter and I told him near the beginning of our session that we wouldn't be coming anymore. We got to use the whole session to wrap things up, tell what we had learned from therapy, say what we needed to continue to work on, etc. It was very nice. He did not try to convince us to stay. He was very professional and respected our autonomy to decide.

Good luck. I don't really know your situation, but I hope you choose to see him one last time...