OK, so I wasn't a c25k dropout, but more of a casualty. I am male, was 58, 306 lb, 6 ft tall. I got no farther than week 2 and my knee ballooned up. I guess trying to start running when that overweight and old can be problematic. I joined a gym and used the eliptical. Then I started attending cross fitclasses. I was usually the only male, but that is ok by me. They nearly killed me but I kept at it. Pretty soon I was doing 90 minutes of cross fit at a time, 5 or 6 days a week. When I was down to 270, I signed up for a Spartan Race that was 8 months away. I knew I needed to be down to at least 235 to survive, but preferably 220. By race day llast August, I was at 215!!! I continued to lose down to 200 lb. Along the way, I discovered trail running. I absolutely love it!!!! So much more fun than pounding the pavement. I started a trail running meetup group in my hometown (Salem,Oregon). My only problem now is that I got too obsessive and pushed to hard, running half marathon distances with steep elevation changes on mountain trails and strained my achilles tendon. Then, stupidly, I refused to rest it and continued running until it was a big knot and I was walking like a zombie. I have not run for 1 1/2 months and have gained 15 lb. I can't wait to get back to running to lose it again. I am not going back to my old ways!!!
I guess all that I can offer is that to get the weight off, you have to watch your food. I logged my food, striving for balance between carbs, protein, and fat (40-40-20) keeping to 2200 calories a day) and lots of hard exercise. If you exercise a lot, you can have quite a few calories and still lose. It gets easier as you go. You just got to get into the habit. It is worth it.