Specks sudden aggressive UPDATE

Speck had a fever,is losing baby teeth & is now on antibiotics and baby aspirin. She was out of control at the vets though. In the few seconds I was writing down her instructions Speck rolled her soft carrier over and over until she reached the end of the waiting room. Even the vet had never seen anything like it. Full moon?
He's calling a behaviorist friend to address her 360 change in attitude. Speck will be spayed the week after next. My sister thinks its PMS-my mom thinks its mad cow. smile :-)

Anyway, the meds are kicking in, we're using tough love with time outs & have switched to a terrier food I found at the pet store which she likes alot.

I did get some advice I'm uncomfortable with.
Someone recommended I quit submissive position & rather aggressively handle her? Grab by the scruff, nail her to the ground yelling no and not let her up. They said dogs only understand pack order and in order for me to be alpha-I guess I have to kick some puppy butt. They said their JRTS dont fear them and they know who's boss. What are your feelings on aggressive handling? I always thought aggressions begets aggression. Am I wrong?