Welcome to 3FC =)
First of all, congratulations for following through on your changes!
At some point in most lifestyle changes, people come to a frustration point. Now, this is very, very important. People get frustrated and often see it like this "Ugh. I'm doing all this work, and the weight isn't coming off like it's supposed. I might as well quit!" ... What happens when those people quit? They go back to the way things were, gaining the weight back and often adding friends to the original number.
How do we work through the frustration? We determine the problem, and we find a solution. This can take time. This is normal. You should still follow your plan, because at the very least it took some weight off to begin with, and should keep you from gaining it all back... as long as you're honesty following the plan.
A) Are you as strict with yourself following the plan now as you were in the beginning?
B) Are you HONEST about your food intake? Are you journaling to see how much you're eating and when?
C) Are you getting in extra activity?
D) Are you bored? Do you need to tweak the plan to fit your life more? Do you need to add in things that will keep you on track and satisfied?
Remember - not all weight is the same. Weight does NOT always equal fat. There's water in your body, bones, muscles, organs, food traveling through your system. Getting on the scale and it saying a number does not mean that the whole of that number is excess fat.
I urge you to try using a tape measure this month. Take your measurements, then take them a month from now as you continue to follow your plan. You might be surprised if the scale doesn't move as much as you'd like... to see that you may be losing inches (which is vastly more important).
There are normal scale fluctuations that go on while a person loses weight. It's over the LONG run (like over many months to a year) that you should start to see patterns and notice that the weight is going down at its own rate.
Keep at it. You'll find the key to move past this little bump in the road.