Ex boyfriends mother trashing me.

I broke up with my boyfriend about 1 month ago, we went out about 8 months. He has been non stop texting, calling driving by etc. His mother has been trashing me online (facebook) every day. She has also called/texted and yelled at me also. She is crazy... They say that I am harrassing him. I am in college, he is a senior in high school. How do I get everyone including the mother to stop trashing me online. Everyday there is a new quote about me. I just want to be left alone. Who is the grown up here? UGHH