Well, those are some lonnnggg posts above me, filled with good advice.
The only thing I want to say is:
Your puppy sounds normal.
Your puppy is VERY young - you are expecting too much.
And I skimmed the other posts but I'm not sure anyone stressed the importance of exercise. Boxer puppies need a lot of exercise, otherwise they *really* are the Tasmanian Devil.
When Mack was that young, he got 2 half hour walks a day (morning and evening) and another 2-3 walks around the block where leash training and basic obedience (w/treat rewards was happening). It is REALLY HARD to give them enough exercise before they have been fully vaccinated - but if you don't do it, they cause chaos.
I think most people learn to like Boxers when they are exposed to adult dogs with some training and maturity. Boxer puppies really are a handful and I feel for you - you probably already have enough to deal with caring for two young children. "Somebody" (read this as your husband) needs to wear out that puppy with regular exercise, or he's going to end up in rescue.