Help me stay on the wagon today

[realhousewife23]

Been low carbing since last Monday, been quite strict trying sticking to 20g per day. Yesterday (Wednesday) I was down 10lbs (I'm sure first few days loss was just bloat after a heavy eating / drinking weekend before I started) and I was feeling really great, the bloat was gone, was feeling great with energy levels better than they have been in months...all good. Was going to try and do 2 weeks of strict 20g then maybe start to re-introduce a few things slowly.

Now today (Thursday) I have put 3lbs back on for overall loss of 7lbs. Am gutted. Thought I stayed on plan yesterday so what would cause a 3lb gain in 1 day? Water retention? I ate a chicken meal last night with sauce that I can't be exactly sure what was in the sauce but it can't result in 3lb gain could it?

I know it's just the scales but this is the sort of thing than could have me going well stuff it, I might as well have some cake and crisps. Anyone got a word of support to get me through the next couple of days and stay on track without caving in entirely? I'll try and have lots of water today (did also have a lot of diet fizzy drinks yesterday) and hope I can stay on track. What do you do when you're having a low day to stay motivated and on track?