Like everyone else has said, it's normal for your cat to get upset over this. This is why it is VERY important to get your cat fixed! Your vet sounds like an idiot... I know you live with your mom (i do too i just turned 18) but you REALLY should have gotten your kitty spayed before this happened. just need to reiterate that as there is a massive over population of cats and dogs... for each kitten you have now there are millions more out there.
it's just normal protective instinct.. sorry she got you so bad though
Once she's weaned and you've found the kittens good homes (try posting ads in pet supply stores or vets offices.. you can charge $50 per kitten and offer a $25 refund once the kitten gets it's shots or is fixed) your mom kitty can get spayed and she will settle down.
All moms get a little crazy sometimes
