Stop being disgusted and take control. Start IP again, and pay lots of attention to the effect that different foods have on you during the journey.
Being upset won't change it, doing something about it will.
We all slip up, but beating yourself up will keep you in that nasty spiral of self-hatred and inability to climb out of the pit you are in.
I've been there. I know how easy it is to regain with bad choices and letting the good habits slide. Now I'm back on program and trying to get back to where I was. It will happen. It can happen for you, too. Won't you join me, and all these other folks?