Hi SFG, and welcome! You will find lots of encouragement here, plus there are many who have gotten in great shape over time. Added to that, there are personal trainers here. Linda (Italianangel) always has great things to share-among many others.
A few tips from me:
1) Get acquainted with the glycemic index, and stay away from high glycemic carbs. My own carb sources are green veg, and brown rice. Get a copy of the South Beach Diet.
2) Get moving! Having alot of extra weight on your frame is tough on the joints as well as your back, so to start with I would suggest that you find something that is low impact. I would also suggest that you find something that you can have fun with-that's also challenging. Walking at a brisk pace, biking (stationary or mobile) dance, workout videos are all good. My girlfriend has recently started taking NIA classes. We know some people who take those classes and they are feeling much better, and for those who need to drop weight, the pounds are sliding off.
Nia | Through Movement We Find Health
If there isn't a class near you, they have DVD's at a very reasonable price. I just bought two.
3) Go out and buy something like a dress or jeans that you really like that is two sizes too small for you. When you reach the goal of being able to wear them, go out and do it again!
4) Stay away from soft drinks. Aspartame stimulates the appetite for carbs, and reg soft drinks are full of poisonous sugar. Sparkling mineral water, and teas are great subs. Green tea has fat burning properties.
5) Don't drink too much caffeine. It stimulates insulin secretion from the pancreas, and that can lead to weight gain.
6) Drink lots of water! Mineral water, distilled water, spring water, water water water! 3-4 liters a day.
7) Find things that make you laugh. Sometimes dieting is tough, and laughing releases endorphins ( a chemical our bodies produce that makes us feel good.) There were times in the past that I should have worn a T-shirt that said, "Caution, Diet in Progress." Nobody likes a grouchy dieter. Besides that, if you find a way to enjoy the journey, you will have much more success.
8) Find a weight-loss buddy.
9) Start some resistance training. The more muscle you have the more calories you burn. Don't worry about looking like a man or getting too much muscle. Unless you take steroids, it's not going to happen. Talk to your doctor about any type of exercise you are considering though. You are very young, but you've also had recent surgery.
10) Meditation. Relax. Take some time for yourself when the 13 month old naps. Visualize feeling better, being healthier, stronger, and thinner. Visualize fitting into the smaller jeans.
All the Best!