You sound about my size. I'm a 25 in jeans and I'm 5'1 and a half...and I'm about 5 - 7 pounds lighter than you. You're not fat at all, what are you talking about? :)

As for dresses, I think just always opt for something that appears short. Long tops might work, too. And yes, black tights always slim your leg down...but it's almost spring hahaha.