Firstly, congrats on getting to 68! That's awesome work!!
Second, plateaus suck! You didn't mention if you stick to a certain amount of calories per day or just 'eat healthy'. If you don't have a set amount of cals you could try working out how much you're consuming each day in cold hard facts. Also, try mixing up your exercise by trying a completely different workout at the gym or get a new work out dvd to use at home that you've never tried. You could also try having your largest (usually dinner) meal at lunchtime and a 'lunch' like meal for dinner. Anything that will make your body go "huh?"
The first two suggestions have worked to get me out of a plateau and the meal swapping has worked for a relo of mine in the same position as you (she couldn't get under 69). Usually plateau's are just your body adjusting to your new lifestyle. Sucky ain't it lol. Also try googling about plateau's, theres heaps of useful tips out there to get things rolling again!
I hope you find something I suggested helpful. Good luck!