Don't panic! You're doing great. 2.4lb a week is outstanding progress, but unlikely to continue at that rate indefinitely. So you put on a pound this week? No worries, give it a few more weeks and see how you're doing. Your diet looks fine to me.
I can be upto 2kg up or down from morning to afternoon depending on when I eat and what, ahem, bodily functions I've performed. You're doing so well, don't lose faith just because of a one week scale anomaly.