It means you are almost at the point of doing something but at the last moment you don't. You stop short. "I had an argument with a guy at the bar last night but I stopped short of punching him in the nose."
Do you have a sentence? Here are some other examples
The golf ball stopped just short of the hole. She told him she cared for him but stopped short of saying “I love you.” The president gave a powerful foreign policy speech denouncing the Russian invasion of Ukraine but he stopped short of declaring war.