Harrassment by boy friend how to stop him from doing so

I was in a relationship with a boy from July 2016. After a few month I have started noticing his controlling nature. We work in same company. Whenever if stop talking to him then he will come outside my ODC chamber and threatn me to come outside or he won't go from there. If am not picking his call then he will start calling my workmates and will trouble them. Then he started torturing me physically. Where he will not let me go to my pg after my work. he will come infront of my pg and will threatn me to come outside or he won't go. These kind of tortures affected me mentally and physically and decided to break up with him. Even after doing he didn't stop harrassing me. It just increased. He will send our earlier chat conversation to my family members. He will keep Threatening me that he won't leave me no matter what. I was so scared to tell all this to my family cuz they will balme me only. I told this all to one of my close friend. He supported me. We came close and got committed. what should I do?