Hi there and welcome to YorkieTalk.
It sounds to me as though your sweetie is have a bad reaction to the vaccines prayers to you and yours. Scary.
Here is a recent thread about lepto, click
here (2018). You'll see than any number of YorkieTalkers don't have the vaccine administered to their pups.
My late senior had a bad reaction to core vaccines when she turned 13. She became lethargic and shakey; we went to the ER and she was treated there.
When my Duchess, who is now five months, was just a little younger than your little one, she did get bordetalla (oral, as I recall), but we didn't get lepto.
Please keep us posted on how things progress. --KarysMom
.