Awwwwww.....first off *HUGS* for you!!!
We are all here for you and we have all been where you are.
You have accomplished so much, don't turn back now. Our bodies are so unpredictable and it's so frustrating. Plus I feel like the more I stress over the scale, the worse it gets.
As long as we stay on our plan, get our exercise in (if that's part of the plan), drink our water and keep doing what works for us, the scale has to comply eventually!
And...there is no way that 2 slices of pizza put that weight on you, no matter what the scale says.
Please hang in there, you owe it to yourself. You are amazing.