Sounds like your servo is a
non
360-degree servo = non continous rotation-servo
additionally: Your posting is like:
saying "I'm sitting on a chair. Please tell me what illness do I have"
wayyy too lessss information to have any clue even for the wildest guessing.
You are working on an informatic project. And what is most needed in an informatic project is information.
Especcially the code you used.
Post your sketch as a code-section like described here