The weight on fitness

I was always thin, from a little wee child until adulthood. I'm 5'3, and typically range between 105 and 125 pounds (I know it's a wide range but I have IBD which can have an affect on weight gain/loss). Then about a year ago I started to gain a lot of weight. I got to the point that I went to my doctor and told him about my concern. He said he noticed the weight gain and said "I don't want you to gain any more weight either.". No one has ever said that to me before, so at this point I knew that I had started to lose control over my weight. I'm used to eating whatever I want and not having to excercise to keep thin but I suppose that's changing! So finally he weighs me and the scale says (keep in mind I had a full outfit on, including my shoes), 154 pounds. Yikes. I'm definitely overweight. Even if you take off a couple of pounds due to my clothing, I'm still at least 20 pounds overweight. My BMI (body mass index) is 26.9 if I punch in 152 pounds. Overweight begins at a 25 BMI. (To calculate my BMI I went here.).

Here are some pics of me over the last few years from when I started to gain:

It's hard to see how thin I am here but I'm probably at a perfect weight, on the low side of a healthy BMI. I would like to get back to this if not a little heavier.

Here I believe I started to be overweight. I don't think I look that big at all, but I am all fat and no muscle.

This is me last November, probably about 10 pounds lighter than I am now.

Fashion Note: I haven't been the most fashionable person as you can see, but my blog is about learning from my fashion icons, which is a post that will be going up soon. Reinvent your style with me!

I dont have a current pic of myself but I think it is really visible, especially in my face! Soon I'll be posting a new photo of myself along with my goals for this year.

Is anyone up for a fitness challenge?