Diet + gym = misery

OK, so the wife and I have been on a joint-venture diet for a couple of months now, and we're actually doing pretty well, although I feel like we've been slipping a bit over the last week or so. Last week was especially rough for me since I ended up going to a lot of after-hours work functions at which I was offered free beer - and let's face it, I can't turn down free beer. A friend of our was leaving NY and had a party at the Spotted Pig (they have a fantastic burger smothered in Roquefort), Clau had two midterm exams last week and needed some beers to chill out, Sam cooked and invited us over to eat the food (Sam's a really good cook so you can't turn that down), etc etc. You know how it goes - when it rains, it pours.
So, to make myself feel somewhat less guilty, I've gone to the gym slightly more than usual lately (well, going at all is really slightly more than usual for me). Normally I just chug on the elliptical treadmill for 30 minutes or so, since every other type of cardio is a bit hard on my knees (they really started to give me trouble in my mid-20's - all that basketball in my youth probably messed them up good). I decided yesterday that I should try the 30-minute abdominals group class, figuring I'd maybe speed up the shrinking of my beer gut, and I could get about 20 minutes of cardio afterward.
Oh man, was that ever a bad judgement call. After the ab class I basically stumbled home, with only the thought of not passing out or puking on the sidewalk, and I just wanted to make it into (and out of) the shower before every muscle in my midsection and back locked up and prevented me from moving again. I actually felt better after the shower and was able to function, but today I have aches in places where I wasn't even aware I had muscles. I don't know how I'll convince myself to ever do that again.
The funny thing about exercise, diet, etc is that it's all so damn hard in the beginning. I'm sure that if I stick with the ab classes (although just the thought makes everything hurt even more), I'll end up getting through it and even enjoying it, and I'll wonder what I thought was so hard about it in the first place. Dieting is the same way; you feel so damn hungry all the time, but after a couple of weeks it just feels normal, and eating something you used to have no problem with (like a big-ass burger and fries) makes you feel sort of queasy. So, I think I'm going to try to tough it out, maybe I can have a nice flat stomach for swimsuit season (truthfully, I'd be content to just not be embarrassed on the beach). Today, however, I'll be proud of myself if I can just get back on that elliptical machine for 20 minutes and not spend the evening playing video games instead.
Overall, the diet's been a really positive experience. Both Clau and I have lost somewhere between 5 and 10 percent of our original body weight, and we're both feeling a lot better in general. She's going to be on a business trip for the next couple of weeks, hopefully she'll be able to stick to it (although I certainly won't blame her if she can't), and I'm going to try to work out every day, since I won't be sacrificing any time spent with her. Hopefully she can come home to a man who's in considerably better shape than I am now. But more likely is that I'll just end up hanging around and watching TV. Hey, at least I know myself.