A lot of people lose weight on the Atkins or South Beach diet or a similar low carb plan - the science behind it is pretty good.
However...you might want to prepare yourself for the possibility that losing weight may not save your relationship. You might also consider whether you really want to commit yourself long-term to a relationship which is dependent on you being thin. Life has a lot of ups and downs (even physically, people change - people get medical problems, women have babies, and so on), and ideally people should be there for each other and support each other through the challenging times.
Last edited by Sundial; 08-08-2013 at 04:49 PM.