Jessi, welcome! You're gonna love this place.
My advice is to try not to focus on having 100 pounds to go. It is just waaaay too overwhelming and can too easily lead you to give up because you think you can't.
That's like looking at a huge mountain and thinking you could never climb it. When all you really need to do is look at the ground in front of you and take one small step, over and over again.
Focus on 5 lbs or 10 lbs. Visualize yourself being successful. Imagine it. See it. Believe it.
Don't expect to be perfect. And always remember that you're only one meal away from healthy eating.