I am re setting my toilet, I have a 3/8" bendable crome supply line. When connecting to the toilet I have a plastic nut, plastic washer, and rubber cone, in what order do they go on? I placed the rubber cone inside the plastic nut, then placed the plastic washer in, then slid the line into the nut. When all the components are in there I can't get the threads to start. What am I doing wrong?