Well, in situations like this, I'm a big fan of the idea that knowledge is power.
- see an attorney to get a reasonable idea of what your financial situation might look like if you divorced.
- if you can't decide if you are being paranoid or if H is really still up to something, pay for a P.I. to find out or find some way to confirm it to your satisfaction (not sure how legal it is, but one person here put a voice-activated recorder in her H's car and was able to hear him talking to OW and making plans to leave wife for her).
- even if you decide to stay, start making financial contingency plans - pay off debts, get needed dental work done, stock away a little emergency cash, make copies of financial documents, etc. Better to be prepared in case H does go off the deep end one day.
- check out the Ultimate Retirement Calculator at financial mentor dot com - the easiest and most complete one I've used, can help you run some scenarios.
- run credit checks to make sure your H isn't doing anything screwy with money, like running up big credit card debts.