Last day of Whole 30

Did you actually do the Whole 30, or did you do some bastardised version of it? Because if you actually did the Whole 30 (and read up on the program before undertaking it), you'd know exactly what do do when it finishes, because they are very clear and helpful about that.

It's an elimination diet to assess food intolerance. Once finished, you're supposed to introduce the food groups you cut out one at a time, one a week, and see how it makes you feel and assess if you have any negative reaction to that food group. You're not supposed to add back more than 1 at a time, because you won't know what's causing the reaction.

So a pizza, with at least wheat and dairy, probably some sulphites, would completely blow the point of doing an elimination diet to assess intolerances, which is what the Whole 30 is.

Why are the choices W30 or paleo or junk food?

The things that make W30/paleo unique have nothing to do with junk food or not. It's the elimination of legumes (for most a very healthy addition to the diet), grains (including whole grains, a very healthy addition to the diet), and dairy (for those without lactose intolerance, can be a healthy source of protein and probiotics).

I considered W30 and did do paleo for a while, but I thought the eliminations made no sense and eventually thought about the fact that I am not going to overeat beans or lentils or whole grains or even greek yogurt, and that by eliminating those foods I was forcing myself to rely more on meat for protein. I already mostly cooked from whole foods, had for years, and limited so called junk food either because I don't like most packaged junk foods or because that's an obvious thing to limit if eating a healthy diet. The things I liked about paleo (focus on vegetables, cooking from whole foods, sourcing meat carefully, eating the whole animal) were things I favored and tried to do before paleo and were not specific to paleo, and the things that were struck me as pointless.

That said, if for some reason doing paleo is the only thing that keeps you eating a healthy diet (although I'm not sure why that would be), it won't hurt you and can be very healthy. It's just not healthier than sensible healthy diets that include whole grains (or even some refined grains), legumes, and dairy.

Anyway, as for what you should do, my recommendation is to think about what was helpful about W30? Is it that it inspired you to cook more than you did before? To eat vegetables? To not overdo foods you tended to overdo? To cut out unplanned snacking, since it wasn't compliant? Keep doing those things, but if there are some foods you really missed, maybe find a way to include them in moderation.