Kimmy is right. Don't give up! But I agree, it is time to change what you are doing. It may be time to reduce your calories a little bit, or find some different foods and change out some of your usual fare. And altering your workout would be a good idea as well. No doubt the muscles you have been using are really strong now, and have become accustom to what you are doing, so you need to find some new moves to challenge your body again.
You can do it!