Advice on losing fast? Two thoughts. Log what you eat and be aware, make good choices, and, given that you have 100 pounds to lose, the weight probably will come off fairly quickly at first. Second, once you fall into the routine and get past the initial drop, slow and steady wins this race. Weight lost fast is more likely to come back; it's recommended to lose about a pound or two a week, though depending on where you start, you may see more than that, especially at first.
Take a look around the forums; you'll find lots of advice and tips. There is a thread in the Weight Loss section for 100+ pounds to lose that might be very helpful, and the 7-Day Motivational Thread in the Women's Corner is very welcoming and motivating. Hope to see you around!
And now that you don't have to be perfect, you can be good.