If you have obsessive/addictive tendencies... perhaps it is truly best to define an end point and stop cold turkey... then treat your uneasiness after, with the other T. You may not feel ready to just leave the toxic therapist, but do we ever feel ready to quit an addictive behavior? Waiting for a time to be ready for that might turn out much more destructive than the discomfort felt about stopping.

I had a T in the past who was not a good fit for me and was actually feeding (not causing!) my addiction. I am still very glad that I did not give in to his manipulations, left and found a new T who was actually helpful with my obsessive tendencies and provided a positive, reliable relationship instead of stress and discomfort. It was uncomfortable for a while when I left the first T but nothing too severe and it dissipated rather quickly. I think if I had tried to just see him less often, that would not have helped to move me out of a mostly negative and unhelpful context. Much like the feature that most people who are addicted to a substance can only truly get better with complete abstinence. Which is of course very challenging to achieve but as you know, probably the only viable solution.