I think you should give yourself a break, you are doing really well, so be good during the week, & let your hair down (a little) on the weekend, then get back into it next week, this way you can have a bit of both worlds & you won't feel deprived. In the long run, you will find that you won't be as bad, if you know that you can have it, "both ways" Just don't over do it!!
Hope this helps, it's what I usually do, & it makes me stick to it dilligently during the week, so I don't feel guilty later.
Beanie