Maybe you should look up what a therapist is allowed to do/has to do where you live, and who will be able to know what you tell your therapist, and what they are allowed to do with that.
As far as I know, usually, only your therapist will know what you've told them. They can't tell anyone else what you tell them. Unless you're specifically planning to hurt yourself or another specific person, then they may have to report it. But that's not the case, so I think they aren't allowed to report this if they even wanted to. Usually a therapist would try and get you to get yourself the help you need, but your friend can just refuse.