You are confusing categories. An event that has happened in history is an objective reality. Take the assasination of JFK. Even though this event did not happen before 1963, that does not mean that it is not objectively true. Just because there may be someone in a third world who never even heard of JFK, it still does not negate the fact that objectively JFK did actually live and die even if though millions in the third world are not even aware of this.
This is YOUR problem. If an event that comes into being, and is not known to everyone in this planet, is not an objective truth, then your own existence is objectively true. There was a time that you did not exist. And unless you are a very famous celebrity, only a tiny percent of the people are aware of your existence. So would you agreee that you do not objectively exist?
You are confusing ultimate, necessary existence with contingent existence. An ultimate, necessary existence would always exist. This is God. And only God is Absolute Truth. And any attributes of God, such as love or purity would also be absolute truth. Contingent existence is not necessary existence. A contingent being does not have to exist, and there was a time that the contingent being did not exist. We and all creation are contingent. There was a time that we did not exist. We are not absolute truth. Only God is absolute truth. But it is objectively true that we exist. My existence does not depend on what percentage of people believe in my existence. My existence is not relative but objectvely true. But since I am not a necessary being, there was a time when I did exist. This only means my existence is not absolutely true. But my existence is still objectively true.