Darn it, me! What are you doing?! Stop this madness right now! Stop it!
I'm pretty sure the me from this time last year would cry to see me now. She'd give up, actually, seeing that all her planned hard work was just going to go to waste in a few months time.
First, you haven't completely undone all your work because your current weight is still less than your starting weight. You've slipped and you don't like where you landed. That's part of being human. Now, what will define your direction is what you choose to do about that slip into unhappiness. You know what you need to do to get that scales going in the right direction and you can do it!
I am with ya. I am about 35lbs from where I was last year. You have not undone everything, you have just had a minor set back. Life happens, it happens. I beat myself up about it for six months, that did not work, the weight was still there and actually I hit my new (and last) highest weight. I had to just recommit and not take any excuses that my stupid sabotaging body/brain was throwing at me and push through it with my good healthy brain that wants to stick around for a LONG time.