I go on spark while I'm at work, so I'm fortunate to be able to do so. And I also am on spark in the evenings for about 30 minutes. I also am a single woman, no children, and only have a cat at home that doesn't demand too much attention. I'm sure finding time for yourself is not easy. But, its all up to you. Your choices determine your future. I've had a history of depression, and diet/exercise keep my depression away. I make healthy choices because I don't like feeling depressed.
You'll have to find the strength within yourself to support yourself. You're the only one who's going to make decisions for yourself. I eat junkfood once a day or every other day, but I just have a very small amount of junk food, I don't pig out on it. And I also used to set aside one day to just do whatever I want. I used to call them my "I don't give a f Saturdays." But now, I've changed it to 2 days a month where "I don't give a f." Yesterday, I had a two fun size snickers bar. You can totally have the snacks you love, you just have to have them in moderation and add them to your nutrition calculator.
For me, it took a couple years to really start using spark for all its features, every day. It wasn't until I found the determination within myself to actually do it.
Every day, I log into SP and I click on "SparkPoints." There's a checklist of things that the site has to offer. Going through that checklist (or half of it) keeps me motivated, very much.
Maybe you can get up earlier, before the kids, and do 10 minutes. Maybe you can sneak away while the kids are playing (not sure how old they are) and take 10 minutes. Maybe you can sneak away twice at 10 minute intervals. If you do 10 mins in the morning, 10 in the afternoon, and 10 in the evening, it adds up.