I agree with Dixieland Dancer wholeheartedly.

This situation is already out of your control - thank goodness you recognise that and are so willing to rectify it!

I can be of little help to you over the internet on this as without being able to demonstrate the techniques and actually watch you with the dog it is impossible to be effective enough fast enough.

Let's make no mistake - you have the beginings of BIG trouble on your hands.

In your favour you have an open ear and mind, determination and loyalty and love for your dog.

I STRONGLY advise you to seek a behaviourist.
If anyone you contact says that the dog is being over protective of you - you do not want that person to fix your problem.
Find someone who will work on the pack order and help you get the dog to accept his place.
I also believe that you need some form of physical control - keep the dog muzzled when there are other people in the house until you are certain you can control his behaviour and invest in a prong collar and learn how to use it properly.

You CAN overcome these problems but you must have guidance and more help than I can give in this situation over the internet.

Good luck, you CAN do it! Do seek help as soon as you can and please let us know how you get on - I will be thinking of you.