Failing by Self Sabotage

I chose losing 40 pounds for my 2019 goal. That would put me in the 140’s, which is WAY outside my confort zone. When I looked at my list of impossible goals this one jumped right out at me as the obvious one to go for. My question is around planning my fails. What does that look like in the overeating realm? I don’t want to self sabotage and plan to buffer with food, right? I’m planning to attempt intermittent fasting, which will likely bring up a multitude of thoughts and feelings that I will need to notice and do models on, but again, I would prefer to not be happy if I fail as it would be because I didn’t show up and manage my mind. Most of the examples I’m hearing seem to be about people putting themselves out there in various ways and then the failure would be when others don’t respond in the desired way, by dating you or paying for your services. I’m trying hard not to dwell in confusion over this, but would love some examples and clarification on whether I chose a proper goal.