Oh Orla I feel your pain it is so disheartening when it happens, but you really should try and stay off your scales, it just does us no good. We see the number we don't want to see on our own scales and then we can just sabotage ourselves.
I think when we have come as far as we have things slow at a little too and something needs to be mixed up a bit. Try to measure out your milk and drink it all if there is any left at the end of the day. I still measure mine after a year. Keep a little notebook too so you can write down what you are having, it doesn't need to be the SW food diary. I hope your official weigh in goes well xx