I can relate to this. At the moment I'm sort of ''stable''. Last session me an T actually talked a bit about that. If working on staying table with the new T for the 5 months current T is away is enough for me. Maybe I'll make some progress, but that the focus is mainly on staying stable during the months T is on leave.
For me it isn't enough. I won't make it too long, but eventhough I'm not as bad as I was before 5 months ago and I'm now sort of ''stable'', I still don't feel good. And like how I am now, I won't make it through the first few weeks of college, which starts in September.

Last year I did talk about my difficult stuff with T. I didn't do that the first time I was in therapy with current T. Then the main issue was social anxiety, now it's depression. I did thought about bringing those difficult things up, but I was afraid to do that and I thought it isn't really that neccessary. But I think a part of falling into this deep severe depression were because of some of those difficult things I didn't talked about.

Everyone is different. Maybe you don't need to talk about your things. Or maybe if you don't talk about it now, you will get less ''stable'' again after some months, years without therapy.
You need to think good about it. And you can do it at your own pace. You don't have to do what you T think you should do or is good for you. And you can tell what you want to tell.