My ten week old puppy (Italian Mastiff x Rottweiler x Bouvier) is giving me the work out. She is mostly okay, has learned the tsst! noise means stop whatever you're doing NOW. However, when she's tired and over threshold, she just gets out of control, leaping at me to BITE me, not just nibble. Today, I lost it, and gave her a very harsh correction with the leash (rope around her neck) which made her yelp (mostly with surprise, I'm sure, as I've never corrected her like that). She's now gone into hiding. Was that too harsh? Am I ruining my beautiful pup? PS: I'm somewhat disabled, with MS, so she's got the advantage. Any ideas? Other than this issue, she's very quick to learn, in the less than two weeks here.