Read this thread:
Fluctuations in Scale Weight and Water Weight
You CANNOT let 2 lbs mess you up that badly. Everything affects your weight - even if you're perfectly on plan you could gain a couple of pounds of waterweight if you ate more salt one day, or if your period is about to start, or if you're ovulating, or if the humidity is up ... all kinds of things.
2 lbs in a 24 hour period is a blip. It's very likely not fat ... just something that will resolve itself.