Welcome to the MLC "club". We are all unwilling members. Your H sure has the classic signs and as you probably already know, there are no quick fixes. As a matter of fact YOU CAN'T fix it, he has to go through this all by himself.
I can relate to your pain. My WH of 32 years left me and D16 in January for "the one". I've been dealing with his drama since I discovered the affair in September 09. The rollercoaster never stops.
Best thing you can do for you and your kids is to GAL and try not to think about what he does. If he is invading your space, set some boundaries. I know easier said then done.
From what I've heard since there is no OW (soul-mate) there is a chance that he may go through "Replay" faster. But there are no rules, each case is different.
If he is spending money like there is no tomorrow, you have to try to protect your interests. Maybe a separation agreement?
Take care of you and the kids
M53 H54 D17 M33Y T38Y Bomb OW 09/09 OUT 10/09 BACK 11/09 OUT 01/10 WANTS TO R 04/10 BACK with OW 05/10 Wants to Reconcile 05/11 I said NO