FIB - there was definitely nothing about your wife's behavior during the whole thing that would suggest you should EVER trust her again.
I'm glad for your sake though that the original OM is out of the picture. It's a lot easier to deal with them dating someone who wasn't the OP. (My ex is remarrying soon, but he didn't start dating this particular woman until a year after we separated, so I don't have any particular animosity towards her - I'm just glad it wasn't one of his affair partners.)
I applaud you for putting your kids first. Even though my kids are in their 20's, and I've dated several men in the 4 1/2 years since my marriage blew up, they are only now meeting a man I am dating. Even at their age, it's hard for them.
Nonetheless - it IS time you stepped off the plate and started dating, or you may sink into something I've seen too much of - 50-something men who have become content to be hermits, occasionally dating when their flagging libidos flare up, but otherwise keeping women at arms length.
Just dip your toe in - honest, the water's a bit choppy, but you get used to it
