"I'm scared that he is sleeping with someone." I think you know that is a real possibility (sorry).
"I'm scared he wants a divorce" Right now he doesn't know what he wants.
"I'm scared he doesn't love me anymore" He doesn't love himself, so he does not have the capacity to truly love anyone else.
"I'm scared I'm nothing without him" No way. You are one awesome woman. You have proved to yourself, your family and your friends (that includes all of us chickens here) that you are anything but nothing.
Please know I am not disregarding your feelings of fear; we all have those same ones and probably a lot more. Don't let them paralyze you. It is when we stop moving forward that our fears overwhelm us and stop us in our tracks.
The big loser here is your H. The day will come when he leaves La-La-Land and sees everything he's lost. And that will be one big dose of scary for him.
Big hugs to you.
H 56 W 48 D27,S21 SS25 SS22 Severely autistic M(#2 for both) 9 1/2 yrs. "I've never loved you" 3/7/2011 Separated 8/7/2011 BITS