Pantheism is a religious perspective that proposes that God fills us and is part of the universe. The pan in pantheism means all. God is all and is in all. If pantheism is correct, then the universe is pervaded by God, in which case you and I have a piece of God in us. If pantheism is true, then God is not personal. If pantheism is true then the universe itself must be eternal because if God is a part of creation, then the universe cannot have been created by God. Pantheism is the religious presupposition of Star Wars, of the Matrix movies and of Cameron’s movie Avatar. It is the religious view of Hinduism and, debatably, of Buddhism.
The problem with these proposals of pantheism is that they are not true. You are not God and I am not God. God was not created, but you and I were created. If God was not created, but you and I are created, then pantheism is not true. Pantheism is false because God is personal. God is a “person.” God can be known. If pantheism is true, then one cannot have a relationship with God, but we can have a relationship with God. Pantheism is not true because the universe is not eternal. The universe was created. This is a scientific fact (or it certainly appears to be true from all the evidence). If it is established that the universe once did not exist–that it is created, then the cosmology of Pantheism is upended. You should note that the cosmologies of Buddhism, Jainism and Hinduism are all cyclic, with the universe always being recreated out of existing substance. Pantheism requires this, but it is simply not true.
If pantheism were true, then the “best” one could hope for is to be reincarnated. In that case, as you say above, our personhood would be illusory. The goal of pantheism is that one cease to exist–to be dissolved into the universal soul/mind. If this were true, then, as depressing as it is, we would need to accept the implications. But it is not true. God is a person. God was not created. We were created. The universe was created. Therefore we are not God and pantheism is untrue.
I have no intention of disrespecting those who take on Hinduism of Taoism or Buddhism (or New Age religion for that matter). I am sure some of these people are sincere in their belief. However, this is a false idea. It is disproved by the nature of reality, as described above. It is also disproved by the life, death and resurrection of Jesus, who fulfilled the prophecies and expectation of the Old Testament, who walked on water, who healed the blind, the deaf and the lame, who calmed the storm, who made bread and fish and who raised Lazarus from the dead. The life of Jesus and the miracles of Jesus prove who he is. At the same time, Jesus claimed to be God. “Before Abraham was born, I AM.” God is a person.
I hope this gives you something to chew on, and that your journey may be coming in for a landing.