Demons know all about a person's past, because they observe them. Also, they can tell you all about a dead relative, and even impersonate that person. for the same reason. We have demons all around us who observe everything we do, and they report back to the devil, who accuses us before God when we do something wrong. But Jesus is a defence lawyer in heaven, and so the devil doesn't get anywhere.
But if you asked a psychic what is going to happen in the future, they will give vague answers, because demons don't know the future. This is why a fortune teller is quite vague when someone asks for an indication of their future. It is the same with horoscopes. They are written in very general terms, not specific, because the demons behind them don't know the future for anyone. Only God knows what the future for anyone is going to be, because He is planning it.
Even though a psychic's experience is similar to your own, it just shows that a counterfeit can be so close to the real thing that it is difficult to tell them apart. Sometimes the supernatural gift of discerning of spirits is needed. But the aim of Holy Ghost manifestations is to strengthen a believer's faith in Christ and to enhance his experience with God and his life. A psychic will draw attention to himself and will draw a person away from faith in Christ and holy living. New Age psychic is all about improving the person in themselves instead of bringing them closer to God for the Holy Spirit to bring the changes.
What I suggest you do is to cover yourself with the blood of Jesus before you come into contact with him. Bind every spirit that is not of God so they cannot influence you in any way; assert that you are a child of God and that the devil cannot come anywhere near you. Then enjoy your friendship, and he will enjoy yours and he will be strangely silent about the psychic part of him, because it will not work in your presence and will not be able to speak through him because you have bound and silenced the demon behind it. The demon will be frustrated as heck, because it will will be imprisoned in chains while you are with your friend, and your friend will relate to you as the person he is and not as a psychic. The Jesus in you is greater than the demon in him, and the demon knows it and will not even attempt to do anything to you. We don't need to be afraid of demons or psychics because we have authority over them. Pray that any curses you receive from demonised people, will be turned into blessings from God. What Graham Cooke says that when he gets a demonic curse put on him, he writes it down and reverse engineers it to make it word the exact opposite, turning into a prophecy from the Lord. Often when a witch puts a curse on him, he says, "Is that all you've got? I've heard better. You're not a very good witch, are you?" That derails them. Isn't that amazing, or what?