I'm new. And I'm also not very good at this whole introducing myself thing, but I'll give it a shot.
I'm a 23-year-old college student in Alabama. I'll be graduating this year with a BS in physics and, well, I'm still working on figuring out what I'm going to do with that.
In 2010, I dropped from 162 lb (BMI 29.2) to 112 lb (BMI 20.2) in a healthy way. I managed to maintain my weight for quite some time. However, in Februrary of this year, I went through a very difficult time in my life precipitated by breaking off my engagement to someone I thought I'd be with forever. Unfortunately, I didn't exactly use the best coping skills when this happened and now I find myself sitting at 138 lb, right on the borderline between "healthy" and "overweight" and no longer feeling as fit, strong, and healthy as I was. I realize that in comparison to some of the fantastic journeys that some people on this site have made, that isn't much. But it's enough for me.
Two days ago, a year from the date my former fiancé proposed, I decided to make a change. I'm tired of letting this control my life the way is has for the last few months. I have allowed it to wreak havoc on my health and my body and on my academics and social life. I am ready to get back in the driver's seat.
But I need help, because going about this alone seems nearly impossible.
My goal is not really to hit a certain weight or size, but I do know that I have been at my most healthy in the 110-ish range, so I'll use that as a general guideline. The last thing I want is to get caught in the trap of allowing numbers to define my self-worth. I don't expect this to be a quick or easy undertaking.
Thanks in advance for accepting me into the fold. A wonderfully supportive place like this is precisely what I need.
Before I ask you for help with my physics homework (kidding), let me just say, congratulations on your decision to improve your health. It sounds like you have an exceptional attitude and the right frame of mind to knock out those extra lbs in no time. 
Good luck!