I hit my late 20's and my oh so fast metabolism decided it was tired. Start watching what you eat in terms of eating in moderation instead of however much you want of whatever you want. I am not a fan of traditional diets as I tried them and ended up binging. So... now I eat what i want, I just watch how much of it I eat. I have managed to lose about 20 lbs. but still need to lose another 30 or so.
As to exercise, just take it slow. You need to get your heart rate up for 30 minutes three times a week, but that could just mean taking a walk around the neighborhood. It doesn't mean doing aerobics till you're all sweaty and exhausted and uncomfortable.
I heard an approach that really made sense to me. I'm trying it and thus far is works. Set your goals, but take baby steps to get there. Forward progress at any rate is good progress, so to keep yourself going without being overwhelmed - just take small steps. The more you push and force yourself, the harder you are making it for yourself to be succesful. Any progress is good, so don't belittle it, no matter how tiny.
And yes, Curves sounds great to me, too. I keep thinking that would be a good thing for me to do. My stepmama went there and really enjoyed it and lost a ton of weight. She says it's a very non-judgmental and supportive environment.
I am female, and was born in 1972 with Lamellar Ichthyosis.