You're an inspiration to people like me!
As far as confidence goes... I think we all face that at some point. When I'm confronted with my own fear, I use the 'fake it til you make it' approach -- I pretend! I add a healthy dose of 'if someone else can do it, so can I' to that. Might not work every time, but works better than I ever expect it to. And don't forget -- you've already succeeded at losing 100 lbs, something many people find difficult if not impossible to do. It's an accomplishment you can be proud of!