Habits!

Valerie
So I wasn't a big Mountain Dew drinker before pregnancy, but OMG I crave it a the time!!! I ask my dr about it they say if I crave it drink it! Just don't over do it! I try drinking juice in the mornings, but it makes me very nauseous! I'm really trying hard to break this habit! But it's not goin so good! I'm 14 weeks! 
What's some of your habits and what's an easy way to break them??