I am glad your current T agrees with your need. I have been in a similar place with a T who thought she could do everything.

My first thought is to make sure you get everything you need from current T at the moment. Make sure the work you two have done together is as solid as it can be.

I would ask current T's help in finding someone. Depending on the nature of things the two T's may be able to work together. A friend of mine was an addictions T and often would find other challenges as his clients became sober. He would then connect them to a T that worked with that issue while continuing to work with them on their sobriety.

I have also cycled back to T's as needed. Did great trauma CBT work with a T then went on to work with another T on other stuff. Later came back to the CBT T for more skills that would help with the Aspi that had been hidden under the trauma.

My guess is that current T is not going to leave you high and dry. They will help you find the right fit, know what you need, know how to interview potential new T's and come to a decision. They will also, I think, help you make the transition over. If down the road new T doesn't work out for some reason I bet current T will be there to help you find someone new.