My weight slowly went up over the course of 4 years following a hysterectomy I just put it down to 'oh well everyone gains weight following that'.
When I twisted my knee and couldn't walk up stairs at work I knew something had to be done.
Started 10th Jan and have so far lost 4stone by August but have since only lost the half stone since sept.
So you will have good days and bad days, just take each day as it comes, but my top tip would be write everything down, have had my best weight losses then and stay to group other people have bad days as well adn you get the best tips.
Good luck.