How can you plateau without getting started?

Ugh I'm so frustrated with my weight! (Understatement of my life...I've been on a diet since I was 6). I started going back to the Y over a month ago, and I've been a rockstar at it (save for last week when I was sick). I'll usually do 30 minutes on the elliptical machine and 10 minutes rowing, and sometimes I'll add strength training. I also got the new Wii Active and was doing that, but for some reason it's hard to make myself do it regularly. This must be a complex I have - I can get my butt to the gym, but I can't go downstairs and turn the Wii on. Go figure.

Anywho, I went from doing NOTHING to doing SOMETHING BIG at least 3 days a week. And my weight stayed the same. No fluctuations, nothing. The. Same. My pants fit differently, mind you, but my numbers didn't budge. Finally after 4 weeks of being pissed off and leaving each WW meeting in tears, I plucked up the courage to talk to the leader about it. My question was, "I figure this is muscle mass; in your experience with clients, how long will it take for me to even out and see a net loss?" Her reply? She thought I might not be eating ENOUGH. Say whaaa? I really didn't think that was right, because I was eating all my points and some/most of those I earned by exercising.

This week I gained 0.6lbs (which probably had something to do with the bucket of fried food and gallon of beer I drank the night prior to weighing in), and she asked me to be dilligent about tracking and share my log with her next week.

Maybe I really have been in denial and have been eating more than I should. I usually ascribe to the "if you bite it, you write it" mentality, though I know I haven't in the past couple weeks. This is a good chance to get back on the plan wholeheartedly, because I know teacher will be checking my homework next week. :/

Oh yeah, I was at a total of -7.4 (since last freaking August, but that's another story), and now I'm back to -6.8. BOOOO. I have a flippin' awesome necklace bought and hidden away for my first 10lbs reward, and I want it sooooooo bad.