You really, really need a hug right now!
It will get better. Decide how you're going to do it and go for it! I calorie count and use exercise videos, but there is a lot of information on this site to help you decide what methods of diet and exercise can best fit your lifestyle. Because that's what it's all about, it what works with your set of variables. But there is something for everyone if they want it badly enough. And don't look at the 70 lbs (I started with 60). Take it 5 to 10 at a time. I don't dare even think about the 30 I have left - I'm just focused on the next 4.
There is nothing worse than feeling you are letting down your child, or embarrassing them. That is a huge part of what got me motivated (my son is 5). I'm 42, and with the extra weight, I really didn't have the energy to keep up with him.
Lately I've been slacking because I feel much better at my current weight (I'm in the healthy range again), but his friend told me this weekend that my legs jiggled when I was putting on sunscreen. When I told her that was because I was fat, she said "Oh no Miss Julia. You're not fat. You're just chubby." Great . . . . back on the diet. 5 year olds are way too honest.