I agree, and with your pdoc and/or T's help, they can help you simplify some explanation that would be appropriate for their age/comprehension.
You can even help assure them that you are working on "getting better" if that would be of any consolation?
I was brought up with the truth, no sugar coating from dad, many times it is best too, so that the child or children do not feel you lied about things when they do not always work out or has changed due to unpredictability.
A thing as simple as getting a vaccination or a tooth filled, mom and dad, especially dad, would tell me the truth, that it may unpleasant for awhile, but in time things will most likely be fine.
My hubby grew up in more of the sugar coated situation, protection from reality, which I feel has made him a person that doesn't handle crisis, in fact when we got a call(s) of family events, hospitalizations and/or deaths, he would find it comforting to put a headset on (ostrich effect) and listen to music instead of getting in the car with me and going to see the person(s) in emergency rooms, their homes, and things of that nature.
The truth, in my opinion, helps people to be able to better prepare themselves for the unknown. That's just my opinion.