First of all, don't beat yourself up over this - I think we've pretty much all been in your shoes, yours truly included.......
Self-awareness is a good thing to have in this case - you know what has happened in your life to bring you back here, and that's half the battle won!
Any number of reasons can cause one to lose momentum and slip - me, I'm a classic "stress eater" who's still struggling with that issue to this day! Since you've been here before, have you gotten involved with SparkTeams? There may be a team or two for runners - that may be a great source of support and advice for you......
Welcome back and best wishes!
If you can't love yourself, how are ya gonna love somebody else? - RuPaul
Take action, and inspiration will follow - Gilad
Change without losing yourself and you can accomplish anything. - Tim Gunn