New T does not have to replace old T in your heart. They are both different, keep the memories and love for old T and embrace that there might be more care for you from another, your new T.
Is it scary and making you want to run away because it is so different and positive than what you know, prepared for and expected. Is it because all your expectations have been blown and you are feeling unsure because you are enjoying it and connecting? I know when things go right for me I want to run or prep for the worst, but I know I should be happy and accept at that time the good things.
Big hug.