Don't give up yet.
Do you have to come by car? Because I'm sure there are good directions online.
If you don't come by car, you have LOTS of choices in the way of buses.
You're from NYC? You can either take Greyhound (which leaves Port Authority ever 1/2 hour, I believe) or Academy bus (you can also get it at Port Authority or East 86th Street). That runs every hour.
http://www.academybus.com
For schedules and fares.
It takes a little over 2 hours, usually, to go directly to Atlantic City. You either want to get off at the Taj directly (if they are offering it), or Showboat or Resorts (all within spitting distance of the Taj).
The hotels? Well, we gave some suggestions, but I believe Priceline offers AC hotels, too. You might get a pretty good deal because it's so close to the weekend. (But that's bidding for a room, not just doing a random search).
I would not sell your tickets at this point because you probably won't get your money back. I'm in the same boat there, with NYC tickets. If you don't mind staying up a bit, you could take the earliest bus back home...they run all night. Or you could hang out in a casino for a while until the sun comes up and then leave.