Yeah writing things down is a good idea.

You could also say something about how you wanted to see a new p-doc (the person you are going to) because you didn't feel like your old one listened to you or took you seriously. That way your new p-doc will know that it is important to you to feel heard and if you don't feel heard then you will move on to seeing someone else as well.

It is always a little scarey meeting someone new. I hope your new p-doc is a better fit with you :-)