I do NOT have the answer, but want you to know you are not alone. My thinking on this shifts from day to day. Some days, I think it is just best to accept that some foods are off-limits. Like cigarettes - I know they aren't good for me, so I choose not to have even 1.
Other days, I feel POd that I have to elimiate foods that are not necessarily unhealthy
if consumed in regular portions. If I feel brave & in control enough to partake, I will chose to not put the entire pizza on the table. I leave it on the stove & take my 1 or two pieces. AS SOON AS I see others are done eating, I get up & put leftovers away in the fridge (or throw them in the trash) or if it is for company, send them home with them. It is the only way to not eat the entire rest of the pizza(s).
I also do not allow myself to be alone with the pizza. Sounds ridiculous - like the pizza can get me or something - but I cannot be trusted. So if it is in the house, I am not to be alone in the kitchen until it is out of the house.
I still end up eating more than I want, but I have had instances of small success with these strategies. Most of the time, I simply avoid it. It is easier in the end...and typically, on my indulgent days, I find it doesn't taste as great as I remember it.
This journey is different for all of us. You will find your way.