Good luck and good for you for being honest with yourself. That's a huge first step.
I have somewhere between 20-30lbs left to lose and I totally get what you're saying about the last bit is the hardest. At the moment I'm just worrying about maintaining my current weight between two business trips, Christmas, and my parents visiting all before the new year.
that being said, it sounds like you know what you need to be doing AND you have a lot of support from your friends/family, which is great!
Oh, and is there anything you can do at work to get in more activity? Like getting a standing desk, taking regular breaks, doing exercises at your desk, etc?