Hello and thank you for sharing information regarding your concern. There is no need to send a note to him since you are ready to move on. You will simply need to be sure that is what you want and then be ready to maintain boundaries if he attempts to contact you in the future. It would be best not to respond to him at all because entertaining him on any level opens the door to allow the potential for more controlling behavior, emotional manipulation and so forth. Change your number and other forms of contact if possible. You need to cut off all ties with him for closure. If you are aware that you do not want the relationship any longer, you do not need to notify him. Focus instead on the situation as a learning experience that you can use to determine what you want for yourself in future relationships. You deserve to be treated with respect and honesty. All the best for your future happiness! You will likely see more clearly once the relationship has been over for a period of time that peace has returned to your life.