First, congrats on busting through the 140s! Take a pause to celebrate!!
I don't understand the phenomenon of celebratory "cheating", but I have the same tendancy. Seems like when I reach a milestone, I cave to a few days of guilt-free tastes, snacks, goodies, whatever & feel like I've earned it. Late night is worst for me, too.
I'm thinking of adding in an evening light workout - pilates, yoga, something quiet & calming to refocus & keep me out of the kitchen. I have a few DVDs at home, and tonight, it seems to have calmed the munchie-monster.
I hope this helps. It isn't much by way of advice, but you are not alone and you WILL get back on track. Keep your end goal in mind & realize that binge eating is not treating yourself with the respect you deserve.
Cheryl