1lb loss is average. Is this your first week? Not everyone has massive losses their first week but they do tend to even out over time. Don't be despondent
If you used a lot of syns on vodka it may not have helped. Technically syns can be used however you wish but there is anecdotal evidence that using them within food rather than for treats helps losses. I'm not sure why but it works for me I know that much. Alcohol also erodes our willpower. On top of that if you are logging them weekly and using a lot in one go that may not help either. Why not post a few days worth of food diaries for people to have a look at?
Using syns on vodka is fine, but when you say you used a lot of syns did you go over your syns, did you measure your vodka, there are a lot of questions you need to ask yourself before being fed up.
1lb at the end of the day is fine, it's a loss & you're in a better position than you were the week before