I had the same issue a few years ago. There is lots of great advice on this thread, and I'm going to throw my hat into the ring too, but understand that you ultimately want to find the solution that works best for you. Losing weight is a very personalized experience and you should not take a one size fits all approach.

First, it is critical that you understand that you need to commit to this for the long haul. There are no quick ways to lose the weight. Ignore anyone or any product that tells you otherwise. To lose it and keep it off you need to take a hard look at your lifestyle and change that.

Second, start small. I used to quit out of doing various routines because I tried to emulate people who were already in shape. I tried running, biking the gym but could never commit to any of them because I was too out of shape and it felt like work. Find something small you can do reliably and stick to it. For me, I started with walking a few extra blocks to the next subway stop instead of getting on at the one right in front of my office. Now if I can walk somewhere in 45 minutes I'll do that instead of taking the subway or a cab. This is how I get my cardio instead of running on a treadmill. You can never outrun the calories that you put into your body.

Soon after I changed my eating habits. I used to have burgers, burritos, pizza and everything else unhealthy every day for lunch. I changed those habits. It took a few months for me to find a rotation of things that were healthy for me, but also left me satisfied. I first found a deli that did a great chicken wrap that tasted delicious, filled me up and was far healthier. Then I found a place that made a chicken salad that satisfied me on every level. Slowly over the better part of a year, I replaced all of the unhealthy lunch options with healthier alternatives. I started asking fast food places to give me half a cup of soda in the smallest size cup they had and then months later I just opted for water where I could. It didn't happen overnight, it took time.

I also started just eating less. Not all at once, but slowly. I noticed that in the past when I went to a salad bar I would need to spend ~$9 for lunch to feel satisfied. Over the course of a year, I managed to get down to spending ~ $5 - $6 and still feel full and happy with lunch. Take one less spoonful, piece of meat etc over time.

Dieting is not something you do for a few months to lose weight, it's a lifestyle change. If I want a burger or burrito I'll still get one, the key is that I won't get one every day.

By this time with just adding walking and adjusting my diet over the course of a year, I noticed I was losing weight. I got a scale and a Fitbit. I checked my weight in the morning and at night, logged my calories consumed and calories burned. It became clear to me that a simple formula of consuming fewer calories and burning more helped my weight drop quickly. This made it easier for me to keep up with my new diet.

Next, I added a home workout routine. It started with just pushups which I could barely do 5 without feeling dead. The key is that I did the 5 I could do every day and kept doing it. Now while I watch TV at home I do as many as I can push myself to, take a break and then do some more when I feel like I'm ready. I can usually do 100 during commercials for a 30-minute broadcast. I've also added in sit-ups and squats. I have no set time to workout, I just do it in between my down time at home.

It's been almost 3 years since I first started paying attention to weight and now I feel better, have more energy and I'm down from a size extra large to medium, and sometimes small depending on the manufacturer.

Find what works for you, start off with small changes and stick with them. Even if you lapse for a week, just pick yourself up and continue pushing.