Scary how to's and now Not to's????

Hi all... I am trying my hand at this AGAIN! First off I should say that I am def a yoyo dieter. So this time (as i said though last time too) I want it to be for REAL! So i have a few questions:

1. How to get motivated and Stay motivated?
2. How do you get back on the wagon after falling off over and over?
3. and this is the most scary question...
How do you lose the weight and look great when your done? I'm mostly referring to loose skin! Loose skin on the stomach, on the boobies, on the butt..... and last but not least on the FACE? How do you prevent it? Sheesh what was scury! <3