How can one stop a sin when his nafs doesn't want to ? Meaning the person want to stop the sin but doesn't find the strength to actually do it though he want to stop. Is it hypocrisy and can you scare me so it help me stop ?

It is not hypocrisy, it is a sin you want to leave, and wanting to leave it is itself good in you. Cut off what leads you back to it, keep away from bad company and hold to the company of the righteous, and Allah Jalla wa Ala says, the meaning of which is, but as for one who feared standing before his Rabb (Lord) and restrained the soul from desire, then Jannah is the refuge (al-Naziat 40 and 41).