Sorry you've had this happen. It's not because you've got a golden cocker . All breeds have problems, it's just that we get a bad name because it is one of the most numerous breeds. A lot of Cockers are extremely sensive in general. They can appear nervous or reactive. As the others say, see a trainer who should suggest a suitable protocol, for the whole household to stick to. Throw out the beeping collar, it would freak me out ! Stick to positive methods. Biting is scary, but to a dog, it's their only resort if they can't run away. Adrenalin is raised by the excitement, resulting in fight or flight. In small dogs, I was told that same amount of adrenalin is released whatever size of dog, so in smaller breeds it takes longer to disperse. So it's stressed out small dogs.
I knew nothing about dog psychology till I had a cocker. In the end, it's very rewarding, believe me,