ANOTHER attempt at being healthy!

Hi all my name is Brooke and I weigh 84 kilos. I'm only 155 cm tall so I'm quite round at the moment lol I'm turning 24 next month and I'd like to live a healthier lifestyle for the rest of my life. I think it's obvious now that I can't do it on my own as I've tried many times. I've lost more than 10 kilos and put it all back on and then some extra for good measure. I've done shake diets, starved myself and tried all protein diets and yes they do work but they suck! Once I lose weight I try to eat 'normally' again and BANG! I'm fat again in less than half the time it took to lose the weight!
Anywho, I have a 4 year old son who will be going to school next year. I'd like to have some more confidence in my appearance when I go back to work or school.
When I was 15 and 16 I ran every day after school. I would work out at night when I was watching Home and Away and I was happy with my appearance, I was a size 10-12 and loved my body. I even had a little 2-pack happening I was so proud! Then I found a guy who wasn't into working out and would make fun of me for working out (he'd laugh and say I looked ridiculous) so I steadily put on weight. It didn't help that he was a junk food freak and would always order me the same amount he ate and get cranky with me if I wouldn't eat it. I know now that it was better for him if no one else wanted me. Hence getting chubby. I had a baby to him in 2008, and I've since gotten out of that bad relationship. I'm happier in myself now than I've been for years, I managed to quit smoking 2 years ago but haven't been able to get rid of the weight and keep it off. I've had a busy time at home with my son, trying to get him prepared for Kinder next year. My Amstaff also gave birth to 15 puppies which completely threw my routine out, I was working out early every morning prior to her giving birth. But being up all night and feeding and cleaning puppies every 2-3 hours put a stop to that. 8 kilos back on in 3 months.
I've signed up for the Ashy Bines Bikini Body Challenge, I've found some great recipes in there that I actually really enjoy eating. Admittedly I screwed my nose up at it first up but it tasted a lot better than it looked! I'm hoping to lose almost 30 kilos. I'd love to be a size 10 again but I'm happy if I don't wobble when I walk. So please wish me luck, I think I'll be needing it.