Hi Mindy, I confess, I'm not a parent either (yet!!), but I did have a thought about the immediate situation regarding the TV. As you said, the deed is done, but that doesn't stop you from establishing some pretty strict rules regarding it! Seriously restricted viewing time on that TV? Or things that have to happen regularly or the TV disappears ---such as various chores, homework, etc? Only certain things at certain times are watched on that TV?
As for the united front with your husband... I'm sure he knows how PO'd you are now so hopefully he'll back up any new rules. I know that down the road I will be the bad guy parent. I always thought myself a real soft touch but but I'm already the bad guy with our pets - the DF is really a soft touch!
Good luck!