Looping when I edit . Please help

When im editing my video, i double click the part when i need to edit and it will loop and i do not know how to take it off. Im going crazy please can someone help. I havd to start over and when i start moving fast i do it every time on addcient and the loop occurs, it will not let me view any other part of the video nor edit any more on the video. Please HELP!!