As Sharron and Pat have said, there is no shame in realizing you are in over your head. It sounds great, a puppy for the kids, but the reality is a puppy that needs hours of attention and energy to become a well socialized animal. You have a huge energy debt..work, 2 kids, a very energetic young dog who has learned a behavior that gets him attention…good or bad, but attention. If the you and the kids are not enjoying him, rehoming him might be a win-win for everyone. He is nipping YOUR kids now, what if he nips one of their friends? And the parents are upset? Potential suits, or worse (for him). Sometimes making the hard decision to find a new home, or return to breeder, is really the best thing for everyone, especially the dog! One persons problem may be just what someone else is needing. It takes a very brave person to look at the reality, not the dream (dogs, kids, fun, fun, fun), and do the best thing for the dog...and for your kids. Not enough energy to go around, so keep it for your kids.
Good luck to you, if you decide to do that you certainly won't be the first or last. Being home and constantly on edge is no fun for anyone.