I don't know any good resourses, but am willing to share my experience.
I was really afraid of losing the ability to dissociate. It served me well over the years. I'm still able to, if need be. Happily I rarely ever need to now.
My alters were afraid they would die or vanish if we/I integrated. Don't know if it is like this for anyone else, but they/we are all still here. The person the outside world sees (what I consider "me") is able to tap into my inner selves as needed. My Little One is/was a terrified 5 year old. I've learned if she starts getting upset I need to look at my life to see why she feels threatened. Or if I feel my inner moorings starting to slip, I need to pay attention to what's causing it.
Again, I don't know if this applies to anyone else, but I view myself as similar to a puzzle block I have. It's made out of clear plastic. Each piece can exist on its own, but they all fit together to make the block. My parts are still all there, but I/we function together as a whole.
Does any of this make sense?