I agree with Jelly, don't think of it as 100lbs just take it 10lbs at a time and you will be amazed that you will be there in no time. Reward yourself for every 10lbs you lose, I myself buy a charm for my pandora bracelet and NEVER take it off. I am constantly reminded of all of the hard work I have done in 25 weeks. YOU CAN and WILL do it...one lb at a time. Remember this is a lifestyle change NOT a diet!!
Welcome to both of you and good luck!