How do i file for a restraining order?

My ex sam (sammy boi of yahoo) will not stop coming to my house my place of work and wontstop emailing me. He has even got his family coming to my house saying that once i have our baby they are putting in for custody as they believe i wont let sam see it when she/he is born but i would what can i do its reallyu stressing me out im scared the stress will lead to a misscarridge.