Hey!

I think that you can’t change someone. However, you can offer them insights that might inspire them to change. That means: Talk to your friend. Make very clear how his behaviour and things he says make you feel, and that it makes you uncomfortable being around him – being constantly judged and criticised is something you just don’t need in your life, and as a friend he should trust you and support you in pursuing things that make you happy. If he really thinks something is wrong he can let you know that in a nice and constructive way.
Don’t give him your “diagnosis”… you are not a therapist and if he really is a narcisist, he will probably not be able to accept it anyways.
You will know by his reaction whether your friendship has a future. Maybe you are important enough to him that he reflects his behaviour and tries to make changes (which will still need a while, and frequent friendly reminders when he falls back in to patterns…)

Good luck!

Dear kateryan: I’m very sorry to hear you’ve been treated so badly! You might want to share your story in an own thread, so people who have been through the same can find it and give you support!