heyy,
firstly its great that you are able to talk about it. alot of people arent aware of ehat it is they are doing until they have done it. If you have particularly sharp nails, cut them and keep them blunt, but nt so much tht you feel nothing, because this will push you to using sharper objects. keep ur nails clean and not jagged as this can help prevent the chances of infection.
Try to work out what the triggers are that happen before you do self harm, and try and avoid those thoughts or find a way to distract you. alternatively, you can try to find a different way to let it out.
Take care
xx