It is daunting, isn't it? Don't be discouraged, because YOU can do it! I joined Curves and that really helped. I lost 12 pounds right away, and found myself with more energy to be a mom. Then I joined the Curves 6 Week Solution (their 6 week weight loss and nutrition course) and lost 12 more. But what I found was a new way to eat that wasn't dieting. I can't stand dieting. I started working out at a gym, and quit going to Curves, but Curves was the spring board that launched my healthier lifestyle. I now weigh 8 pounds less than I did before I had any kids, I run in 5K races and I eat very well. Curves is 30 minutes, 3 times a week.
Or you could workout at home (DVD) in the morning before everyone wakes up. I know you're busy and your days are full, but once you trained yourself to go to bed early and wake up early, you could find that 30 minutes in the morning to do a workout video and then start your morning routine.
All lifestyles, healthy or not, develop out of habit. If you change your habits, you can change your lifestyle. You just have to decide to commit to changing your routine to include a workout. I have to prioritize my workout. Every day I make sure I MAKE time to workout before I do anything else, because it's too easy to let that part of my day slide in favor of something else. I never just HAVE time to work out (who does?), so I have to MAKE time. The same is true for healthy eating choices. I don't ever feel like eating a fresh spinach salad. I'd much rather dive into the ice cream bucket! But I have chosen to be healthier, and with that comes the commitment to better food choices.
It doesn't have to be as drastic as a diet. Start by cutting back soda and dessert, and substituting water and fruit. Like, maybe if you're a big soda drinker try drinking a full glass of water for every soda you drink all day. (Have all the soda you want as long as you drink a full water inbetween each soda...I bet you drink less soda!) Instead of having something sweet after every meal, try just having dessert 3-4 times a week. Or make your desserts fresh strawberries in light cool whip, or 1 square of Ghiradelli dark chocolate. Then try portion control, where you pay attention to your serving sizes. Small changes will have big effects at first.
Get an exercise buddy who is as committed as you are. Even if you don't workout together, you can still be accountable to each other just by staying in daily contact and giving each other daily workout reports.
Believe in yourself, and do it for yourself. It's hard but it's worth it!