How old are your children? Have you reached the point of needing to rehome? Have you talked to the breeder?
Dogs take a dedication, and this breed a lot of dedication. You need to exercise, play, stimulate, crate or watch. That's just the nature of the beast. I always considered dogs a way to teach my child true responsibility. Kid leaves door open or stuff out… replacement of items comes out of their allowance or they do actual real hours of chores to work off the replacement. I promise you a 4 yr old learns to be responsible fast. Did you get the dog for you or the kids? If for them, they have to help... an hour each a day of play or exercise in half hour blocks is not too much to expect! Even if for you, they are part of YOUR family and helping take charge with the dog is truly wonderful training for them too. I promise!
As for your daughter being afraid to discipline for fear of getting hit... gotta ask what type of discipline results in a bite? You may need to revamp discipline or work on the dog if any type of correction leads to bite potential.
I understand overwhelmed, really. But you'll be so much LESS over whelmed if you work out a plan, make your kids be involved, and decrease the dog stress. And if you honestly don't want to, then it's time to call the breeder, or if from bad one/rescue whatever... then contacting rescue to help find a new home. Because unless you commit to the changes needed, it probably is NOT going to get better.