Weight loss will slow down as you get thinner. It's easier to think of weight loss as a percentage thing: you lost X% of your weight this week, rather than Y lbs.
However, in your other thread, you indicated your BMI is over 35 still. You should still be losing weight fairly handily. I imagine your "weekend blowouts" are the culprit.
Can you describe your "blowouts"? What do you consume?