LunasMomma is right, when you've hit bottom theres no place to go but up- and I'd wonder too who told those little ones that they were "bad"?!
The best that I can remember, 3 yr olds don't process things that way!
From the way things sound I think that the very best present that those kids will receive is one that they won't realize for years...you working this hard for their safety (keeping dear old "dad" away) taking them under your wing for Christmas- sounds like a heck of a Christmas to me!
(((BIG HUGS))) to ya!!