I have heard good things about the book that was recommended to you. I hope you will take the time to read it and use the suggestions.
As was mentioned dogs that act like this many times feel they have to be aggressive because they do not have a solid leader in the household. Taking the time to teach him some obedience commands will be very helpful in teaching him that you are the leader. Teaching him to "sit" "stay" "come" will train his brain to obey your voice. Right now he is not responding to you because he does not see you as the authority figure. Apparently he can learn since you did house train him but that is not the end when it comes to training a dog.
Here is a website that has videos and training articles throughout:
DSD Training Videos | Dog Star Daily
You may get some tips there. Taking him to a training class will help socialize him and it will help you learn the tips you need.
The problem you are having can be corrected but it is going to take some work on your part. I hope for the dog's sake and for your family that you take action soon.