19 and joining the family in weight loss

Being..."big" is a family thing....2 of my aunts, my mother, grandmother, 3 uncles and a grandfather are all...well big.
And a lot of them are now doing various weight loss routines.
I'm beign referred for some surgery in about half a year/years time, but the surgeons wont operate on someone my size considering I smoke as well, so here I am making the brave leap into weight loss, with a plan to quit smoking as well. Getting all hyped about it for uni really....