German bombers can’t reach the US east coast in a typical anniversary edition game.
Where are your german bombers taking off from at the start of their turn? Where are they landing at the end if your turn? How far are you allowing them to move in one turn?
I suspect this may be a source of your issue. In anniversary a small fleet is absolutely needed to cover a transport which is in range of enemy air units, but it is typically manageable. However, if you are giving air units freer movement than they are due it could very quickly unbalance the game.