Sounds like a plan! Sounds like a great plan!
If you stick to even half of that plan, I'm sure you'll be happy with the results.
You don't mention your age and height (only your weight and clothes sizes). Size 12 may be fine for your height and age. You may look fine, even your best, at a size 12.
Your boyfriend lost weight with you and put it back on with you. Sounds like your lifestyles intertwine enough so that he is going to be a big influence as you lose this weight. Does he have a plan similar to yours, to lose weight?
Anyway, good luck! You did it before, you can do it again....