Wedding weight loss

Hi there, I am getting married in August 2018 and hoping to lose 3-4 stone by then! Thats eight months of hard work! I just want to look at my wedding photos and remember the happy day and not think 'oh I really should have lost weight'. So here I am looking for help and motivation, I am a huge yo yo dieter , lose a bit, gain a bit.
I am marrying a gorgeous guy who has a great diet and is a lover of the gym (ew!). He never binges or rarely fancies a take away. I need to break my bad habits and find exercise I like!
I am also a midwife and I find shift work, especially night duty, very hard to stay on a diet as you crave carbs on a 13 hour shift! Any help/tips welcome. Hopefully its not just me out there !