I don't know how to answer this. Are you still hoping your marriage can still work out, or are you just done?
Step 4 is best done with a sponsor, as far as I know. Is he really remorseful, or will he just use it against you now, if you told him exactly how you felt?
Never did a step 4, I'm sure other wise people will come along.
(((((((((((hugs)))))))))))))