About 4 years ago, I set out on a similar trajectory. My main aim then was to try and get as fit as possible but the end result was a similar graph. 3.5 Stone lost. However, I well and truly lost my focus and in the 3 year subsequent. I'm now heavier than ever and facing a huge mountain again. Notice and acknowledge when your back off the wagon…. perhaps keep drawing the graph and make a point of publishing it every now and again for accountability. That way, you won't ever need to do it all over again like me.