Trying to loose the Saggy Mummy Belly

Hello There!

I'm 21, and a mummy. I have a horrible fatty overhang/muffin top that i am absolutly desperate to loose. I want to be back to my nice size 12, or at least a size 14. Right now my waist is a size 18.
It's not just 'mummy' fat, it's also because i've been quite depressed, and began to comfort eat. ben & Jerry's - WHOLE TUBS! And a large can of red bull a day.

I'm now begining to do at least a half hour of brisk walking a day, i take my son with me.

Any other mummys that are loosing their fat bits?