First, Congrats on getting back to normal after the holidays!
I don't know if I have any good advice but I am in the same boat right now. I decided to start transitioning to P3 in Dec. I keep making new goals and have been avoiding the switch. It's scary!

Anyway, I have been introducing some "real" sugar back into my diet. Example, I've started eating some Kashi cereal bars for snacks which have like 8g of "real" sugar per bar. I've been adding sugar to my ricotta cheese instead of splenda, ect. I have also tried to add more grains. Eating whole grain crackers for a snack or eating a regular wrap one day in the week. I also eat 2% cheese instead of FF. I actually started doing that in P2 but now I don't really worry about how much of it I eat.
So far, I am still loosing. I lost a pound in Dec. I was loosing about 1 - 1.5 pounds a month in P2. I'm not sure what to do. I really don't want to eat anything "bad" now that I am eating so healthy and I'm afraid that if I increase my portions I will start a downward spiral. Or I guess that's upward spiral, when it comes to weight
Does the new book have any advice? I have an old book that basically says, P3 you know what to do!