Counterfeit Tequila

We bought a bottle of Don Julio for new year's. the first time I tasted it, it seemed super harsh, but I thought maybe it was just me. Last night I had four drinks of it, and we decided it must be counterfeit. It's like drinking lighter fluid. I've had worse tequila, but this was most definitely not Don Julio. I woke up with the worst headache of my life. I barely moved all day. Whatever this was was not for human consumption. I would say where I got ripped off, but I really can't remember. It's some liquor store by minquan rd.