First of all, get rid of the pack mentality thing.....if you hold a dog down, you are scaring them. That is not a way to get a dog to respond to you in a positive way. The only way they can protect themselves from aggressors (you are an aggressor to her) is with their teeth!
Start with simple training ... sit, down, etc and treat and PRAISE her every time she responds. Don't let her have anything without following a command such as sit. For food...for going outside etc.
I suggest you look over this website. Tamar Geller does have online training course, but honestly I don't know anything about it. I DO know that she is highly respected as a dog trainer. You might want to buy her book "The Loved Dog"
The Loved Dog – Tamar Geller's Best Dog Training & Boarding in Los Angeles
Also, I agree with Matese....a visit to the vet is in order to rule out any physical problems.