IHH: I know this is scary, but do what Allen tells you and I promise you will be MUCH better off than if you do not! You will be doing the best thing for yourself, for your kids, and believe it or not - for any chance of saving your marriage.
I've been around this block and I know from experience. My H was not in a proven physical affair and it still took me being strong to get to any state of progress. Now, I didn't move out, but I asked him to move out twice! Long story that I won't go into here, but believe me: showing H that I was not going to stay in an emotionally abusive situation was key. My kids were much better off, I was much better off, and my H has gone from claiming "we could never be happily married again" to now working on the M and behaving like a gentleman, even though we are not fully there yet.
Not only that, but I went through a cheating spouse my first marriage. My moving out was a huge turning point for my own self esteem. Was I scared? Heck yes! Best thing I did though. Eventually H1 wanted me back but it was too late for me.
I've heard all those hurtful things your H has said to you and worse....never saw it coming. It's amazing what a trapped partner will say when they want out. Get tough! Stand up for yourself! You'll feel much better.