I have this idol and i spend everyday trying to be like them, i dress like them, act like them and have the same likes and dislikes but i know i will never truely be like them, so my idol turned more into an obsession, how do i make myself stop before it gets worse?

Don't think about them and just be you.

Don't mirror someone else, otherwise you'll just become a shadow of that person trying to mimic their every action. Whether you realize it or not, you aren't that same as your idol you are different is some ways whether you know it or not. Those itty bitty differences makes up who you are, not them. Don't struggle yo find perfection by copying someone, it won't make you any better as a person and you've set your own limitations by taking theirs. Be who you can be, not what you see as an idol everyday. Make your decisions to further your own life, BECAUSE IT IS YOURS NO ONE ELSES