I trained at Oklahoma State for high school wrestling back in the late 90's. They had a T-Shirt for sale at the training camp that said, "Pain is Temporary, Pride is Forever." However, I just came across this quote from Lance Armstrong and though the Quiting to be more of an impact at this stage in my life. While your pride will get over itself, Quiting is something that will stick with you forever.
Don't give up. Don't quit.