Yes it will hurt him Betterdays. He will be surprised, shocked and wonder what you are doing. Having NC gives you breathing space to think for yourself without being interrupted by him. You also feel for yourself, all of the past hurts that happened before. This is all therapeutic.
I would say, No Contact (for me anyway) was fairly easy though I broke it once and have regretted it ever since. I feel that I gave away the power I was holding and showed him my hand. Breaking NC after having a spell of it, also sends your emotions haywire. But in the whole scheme of things this will really empower you. X*X