highly aggressive and moody cocker spaniel

Question
we own an almost 2 year old golden cocker spaniel called Wesley. we never took him to puppy school but he knows how to sit etc. he barks at everything like he guards the house or something and you cant discipline because he bites you. not just a quick nip they quickly lets go like he realizes hes doing something wrong but literally latches on and wont let go. he becomes so overprotecting and aggressive in bedrooms. you cant go into another bedroom if the person and the dog are there. he goes ballistic like your a complete stranger. sometimes he realizes who you are and is all friendly. its like he has two personalities. What can i do as an owner??

Answer
Wesley has obviously had no training at all and no rules.  But he's still very young and you can correct all this.

I'd suggest (strongly) a qualified dog trainer who will come to your house and teach you how to have a good, stable dog.  At a minimum, he MUST get into some training classes and you have to follow up with daily lessons at home.

For starters, they'll say Wesley is not allowed in bedrooms since that's where he seems to be the worst.

And when you say "you can't discipline" him - just what are you doing?
When he "latches" on - is it a bite or a hold?

Dogs have an ability to gauge their "bite" so I'd like to know the degree of pressure he's using.  If they don't want to "hurt", they won't.  

I can give you some direction on how to correct the barking and the correct way to discipline..which is not yelling or hitting but I need to know more about his general behavior.

Other than bedrooms, does he get aggressive? Like on furniture?
How is he with toys & food?
Is he sociable with other dogs? Strangers?
How is he on walks?
Where does he sleep?
Is he ever confined in the house? (Crate - put in kitchen, etc?)
Does he behave the same way with the whole family or just certain members?
Is he alone all day?

Your problem is basically that Wesley thinks he's "top dog" and the bedroom scenario is typical of that.  It's "his" space and he has to be taught it's YOURS and he can't come in without an invitation.
So for the time being, get some baby gates and he's not allowed in there.

This is all fixable, Carly but it needs to be addressed NOW because this can get worse.  Wesley has no manners because he hasn't been taught any so it's not his fault.  
Delores