I am losing weight this year. The pounds crept up on me over the last 25 years and I found myself 70 lbs over my optimum weight. I am more than half way done and feel better and have more energy.
I think you need to find what works for you. Since you only put on weight after you quit smoking (congratulations, by the way) you probably already know how to balance calorie intake and exercise to maintain your healthy weight, so it is just a matter of getting rid of those pesky 20 lbs.
Some of the things that are working for me:
I keep track of calories and exercise on my Iphone with an app called "The Daily Burn". It also helped me figure out how many calories I need to maintain and/or lose weight. The website is available online, too. There are lots of sites like that and they can be helpful and fun to play with. Check them out.
I don't make time for exercise, I TAKE time for exercise. I am not an exercise enthusiast. Just don't like it, never did. Now, I see it as a daily maintenance routine, just like brushing my teeth or taking a shower. I just do it without thinking much about it. I use a treadmill in the winter, walk in the summer and use some exercise routines I saw in Prevention magazine to improve core strength. Our cable has an exercise channel on demand with all kinds of exercise for all levels of ability. Maybe you have that, too.
For now, I cook a very limited range of foods and measure everything. I tend to stray easily, so it is better for me to know ahead of time what I am going to eat every day. I eat lots of egg whites, broiled or baked fish or chicken, whole grain bread, fresh and frozen veges, and Greek yogurt. I also treat myself with a Skinny Cow frozen treat or 100 calorie pack of snack food every day. Yeah, they are wicked expensive, but they are a treat that I can enjoy while the family is having dessert. Oh, and I have tried a new product, Mio. It is a flavoring you put into water. It tastes great and makes it easier to drink lots of water.
Good luck on your diet. Getting started is the hardest part, but once you get rolling, it is OK.