Therapy goes at your own pace and you can decide what to talk about and when. And how much of something you feel comfortable talking about. You can simply say "I don't want to say more about that right now."

It sounds like those locked away things might be trying to resurface now; maybe your unconscious is letting you know you are stronger and older and wiser now so you can deal with those things by talking about them.

It is scary revealing yourself and wondering what's going to come up.

The very things you talk about in your post--talk about them in your session so you feel more comfrortable.As my T says to me, You are right where you need to be at this time.

You can feel like cancelling the session but you don't have to act on it; you can instead decide to go and talk about how you were thinking of cancelling the session. Everything is something to explore.