Overcoming "Slippery Slope" Mentality

I am new to the program and focused on stopping overeating. I am just starting out with a protocol and notice an issue coming up that I go through repeatedly around the “slippery slope” mentality. If I slip off my plan even a tiny bit, my mind goes to “well you screwed up so forget it, might as well go all out.” When I act this way, it makes me wonder if I even really want to lose weight or if I would rather be able to eat all the food I want. I did the thought model below, but I feel like I’m not necessarily getting to the heart of the issue and I’m not sure if I’m thinking about it the right way and would appreciate feedback.

C: I drank a sip of something not on my protocol
T: I might as well just eat other stuff off plan since Iā€™m already off
F: Relief (at being able to self-soothe and eat/drink whatever I want – it feels like I will truly be able to relax/unwind once I do so)
A: Eat and drink whatever off-protocol junk food I have in the house, including buying and/or ordering additional junk to eat
R: I eat a lot, I buy/order more junk food so that it is also in my house tomorrow and tempting me to eat off protocol again, I feel disappointed in and angry with myself, my weight may increase