Sorry, I didn't say this earlier, but your vet tech is not a trained vet. Trust your gut with this. Only the vet should be giving you advice at this stage. No disrespect to your tech, but truly, I hope you are at the vet right now. If the tech didn't talk to the vet it's not good enough.
I listened to a vet tech tell the owners of a 10 lb dog to feed the dog 7 - 8 cups of their prescription dog food per day! I had to step up and correct her and say no it would be 7/8 of a cup - the dog owners were foreign and the tech didn't have a clue.