Hi Jill, exercise is really the key for me, it helped get me to goal, and it's helping me to maintain my loss. I do strength/weight training twice a week for an hour, as well as cardio 3-4 times a week, usually for an hour. I started on the elliptical crosstrainer even before I had surgery, I love it because it's easy on my knees. I also mix in other things so I won't get too bored, I have done Walk Away the Pounds, also sometimes in the warmer weather I jog in the pool, that's refreshing and different. Recently I've taken up a kickboxing class, which is very hard but fun.
On your treadmill, work on gradually increasing your time and intensity. You can do intervals, which is increasing your speed for a short time and then going back to your slower speed. You can also use the incline to make the workout harder and burn more calories. I find it's best to change it up rather than always doing the same thing, the body seems to respond better that way.
As for food, I try to stick with mostly solid protein, veggies and fruit. I'm sensitive to "white carbs" so I try to stay away from them except for special occasions. This works best for me. I also don't keep junky stuff in my house, this helps me tremendously.
Congrats to you for coming here for help, I'm sure it was hard to come here and admit that you're struggling. Stick with us and we will cheer you on, this is a great group of people and we understand what you're going through.