Hey Emma, i just read your post and wanted to say welcome back, well done for making it back! I haven't read through your diary, will do that later, but the most important step is to make the decision to commit to it again. Although this is my first time on SW, I have been there so many times of losing some, then re-gaining it all especially when life got really tough.
If you have done it before, you can do it again, tell yourself all the reasons why you want to lose weight and think just how much better you feel in yourself every day that you stick to plan. That's what I find helps me big time. When I've had a hard day and all I want is to get my teeth into something sweet and fattening, I just imagine how I would feel about myself afterwards. Or the next day.
So are you re-starting today? Or have you re-started already? Either way, I wish you the best of luck, you can do it!