Your Husband has left you! There is no way you can get him back. He has moved on.
There is no mention of divorce here. You have to move on. Hire yourself a good concellor to help you heal from within. Then hire a good lawyer and file for divorce.
Erm... by whom is he loved very much? You, your kids, the other woman? Or all three?
I guess you could wait a few weeks to see if it's just a short affair (max. 3 months),
though if it is he'll probably continue having them.
Or if you and the other woman are both willing to share him
and he doesn't mind then you could all move together...
But if he left you he's probably gone for good.
What you need now are sympathetic friends
who don't diabolize him.