agressive 6 month old lab

Question
QUESTION: Hi again, I am not a stranger to this page. It always has good advice. This new puppy has been a challenge since almost day one. She has always been somewhat of a biter. First it was puppy mouthing, but now she is getting very aggressive. She seems to get this way when she is very excited or if she jumps on me and I push her off. She gets very aggressive to the pint she begins to lunch, growl and snap if I try to stop her of push her away. She is a good dog for the most part, but this aggression worries me. I am starting dog training tomorrow. Please tell me it is not to late to change this behavior. Is it possible she is just a mean dog, can it be fixed. We love  her so much, but I worry she will bite someone else as she gets older. Please offer some words of wisdom and hope. My old lab was an excitable puppy, but I don't remember mean behavior. HELP!!!

ANSWER: Taking a good class is one of the first things I would suggest.  It needs to be based on positive methods, but focus on you as leader.  It is quite possible after a class for the dog to sit if it gets a treat, but still view itself as top Dog.  

The instructor can see things very hard to reduce to text.  A good instructor should be a big help.  

See how class goes, and get back with me if it doesn't look like it is solving the problems.  Poorly trained labs are much more common than mean ones.  If it is a good class, you should see a big improvement.

---------- FOLLOW-UP ----------

QUESTION: I am at my wits end, I am sitting on the floor crying about this dog. I just caught her leg in the bathroom door by accident as i was trying to grab her collar and push her out of the bathroom while she was literally trying to attack me as I was getting out of tub. I guess she was mad she wanted to come in...I don't know what makes her tick.Now I feel guilty and sad. I have hired a dog trainer, we have had one session..I just don't know or believe this aggression and anger she feels can be helped. I love her so much ...I am so sad she has turned out this way. Are labs usually this mean? Could she possibly not be a pure bred...how can i know? any suggeations?
Thanks again;
Lisa

p.s is my frustration normal or am i blowing things out of proportion

Answer
No, that is not typical of a Lab, or for that matter, most other breeds.  Some dogs are just more difficult than others.  I still thinK the problem is solvable. I hope your trainer is a good one.  One that understands the importance of leadership, but uses positive methods.  You want one that follows Ian Dunbar, not Ceasar Milan.  A top dog is more like amn old fashioned parent, not a drill sargent.