Bulldogs World

Hi everyone. I'm fairly new to the forums, thank you for allowing me to be part of this. We got Vicky about a week ago, she's 9 weeks now. She's awesome and learns super quickly. Our biggest struggle right now is teaching her what she can bite and what she can't, as well as how hard she can "play bite" without hurting us. 

She's amazing when we are inside, she behaves and her play biting is great. She drops things on command (most times) and she comes when being called pretty much 90% of the time, even when no treat is offered. When we are outside in our backyard that's a different story. When I'm with her she becomes very aggressive and starts biting me really hard, sometimes drawing blood and everything/ She usually bites my feet and ankles, but she'll bite me anywhere she can. She starts growling at me and chases me around when I try to ignore her. I've tried everything, the whole "ouch" and walk away. "Ouch" "no" and walk away. Spraying her nose with water when telling her no. I even sprayed her with the hose yesterday because I was so frustrated but I don't want to do that. I try to stay calm and assertive but it doesn't help. Then I ignore her for a while because I don't want to interact with her when i'm in that emotional state. I take her inside and she's back to her chill self.

I just don't know what else to do. She only does this with me. We have a chain link fence and some of our neighbours' dogs bark a lot, any time they see anything or hear anything. I don't know if she does this when she hears them (I think she has done this even when they're not there), maybe it's more of a fear response and I'm the closest thing to her so I get that. Has someone else had this happen to them? How did you fix it? I don't want to ignore it because it will only get worse. She started doing this yesterday, but I notice it is becoming more consistent every time we go outside.