Ok firstly you had a loss which means you are doing something right. Sounds like you've had a bit of a nightmare health week which likely will affect your weight.
Secondly, don't be afraid to use syns, so many people come on here going "I havent lost but I hardly used any syns" as if its a good thing. You would never say the same about super free or free food would you? They are just as important, people often find if they use all their syns they will see better losses.
Thirdly don't lose heart, stick with it, maybe start a food diary on here as a fresh pair of eyes can sometimes see where you could make changes to help boost things. The losses will come x