You're going too slow first of all. Start by hitting it 50-50 with more speed so you're landing further away. Pick that speed up so you don't land so flat.
The rotation is all about being able to turn the upper body while keeping the lower body staying in a straight line. But basically you are just going to slowly rotate the body as you come onto and up the rail. As always, speed is going to make this easier. You can see in your video you approach the rail already rotated, and thus you try to swim it round with your arms. Practice 180's on the flat ground and popping off flat feet, not from an edge, focus on that rotation from the core.
Now that you've got the speed and rotation, when you ride up the pole, bend your knees as you come off to unweight the board and make that spin easier. Keep the knees bent and absorb the landing, in turn helping you land even and not blow out your edge and fall over.