Oh God how terrible for you....you poor thing. As I'm new here I obviously don't know anything about your lovely boys, but I quite imagine that both dogs are probably asleep by now whilst you're worrying yourself to death.
Everything crossed that they will be allowed home tomorrow morning.
Easy for me to say but please don't beat yourself up too badly, accidents happen don't they, and I'm sure if you could turn the clock back you would.
Take care
Jo
xx
P.S. My rescue bullie is terrified of going to the vets and has unfortunately had more than her fair share of visits and admissions in the 2 years since we've had her. She is totally focused on me and absolutely hates it when I have had to leave her there - although all the vet nurses and vets are lovely. I have always tried to make sure she has a piece of my clothing with her to comfort her. I know it's hard to think of everything in an emergency but perhaps you could sit on a couple of T-shirts (for instance) in your car so you would have them to hand whenever necessary.