Everyone has given great advice so far, I'll add my two cents.
First of all, it's a victory to just hang onto the wagon for a week. Seriously, I congratulate myself at every weigh in for sticking with it.
But I know the feeling. I've consistently lost at LEAST 1.5lbs every week since I've started. A couple weeks ago I was slightly off plan, nothing terrible, but I had drifted a bit. I had a loss of .3lbs for the week which was basically nothing since it could just be water weight fluctuations. The week before that, I'd had a huge loss of 2.6lbs. I was disappointed, bummed, and also kind of frightened that I had let myself drift that far. So I took all that energy and focused on buckling down again on plan. I had a 1.5lb loss for this week
Your body will stall, just how it works. I'm guessing this is near the beginning of your weight loss journey? Have you ever watched Biggest Loser when they talk about curse of the 2nd week? They always have amazing losses the first week (like your 8lbs), but then their bodies think "whoa, what's happening, I'm starving...conserve conserve conserve!" and weightloss slows in. Hence, a bad weigh ins.
It happens to all of us, try not to get too hung up on it and just keep sticking with your plan!