Hello - 2 stone in 12/13 weeks?

Hiya, just thought I'd introduce myself. My name is Carly and I'm 37, currently weigh 223lb and would ultimately love to get to around 140 - dont want to be skinny, just fit and healthy. I have a wedding to attend in a just over 12 weeks and don't want to look like a blob in photos. Although I'm not going to be anywhere near 140lb by then, I''m hoping if I can lose 2 stone I should feel a huge difference and it will really give me something to aim for.

Not going to be easy as I adore cooking and baking but here goes!