Stalled weight loss for 6 months??

Has anyone who has had more than 200 pounds to loose ever gone through a stall over six months?  I have not gained anything, I stay 1 or 2 pounds in the same place for six months now.  I still want to loose at least 50 more pounds.  I don't exersize like I should, but I do eat right, and do not cheat, well except for today, I had a small small glass of diet coke.  I hate that I did that, but I am not going to do it again.  I have not tried sugar at all, and am not going to.  I am 15 months out from my surgery.  I am pleased at how much I have lost, but really want to do more.  Anyone else go through this?

Thanks!
Jenny

I bet if you start exercising youll lose the last 50

How many calories a day are you eating? Sometimes bumping up calories/protein can break a stall. It's worked for me. What does your nutritionist say? Six month stall must be very frustrating!