No offense Bahman, but you either have a mental illness with delusions and/or hallucinations, or your attempting something that won’t lead to God. A person with a normal rationale mind knows he exists. He doesn’t need a transcendental experience to prove it to himself.
If you want to discuss how the great philosophers logically proved they, and we, are real, that’s one thing, and you’re on the wrong website for that. But be careful because some of those philosophers went insane trying to do what you want to do. I’m pretty old, I studied philosophy, and sometimes I thought it was silly and not worth my time. Why? Because I never doubted my own existence. If you really feel uncertain that you exist, you may have experienced an emotional trauma as a child that you have totally repressed. Childhood sexual abuse can cause this. Or if you witnessed a murder, or your mother being beaten, when you were a child, that too can cause this.
But if you’re a grown adult with no mental issues, and you want to experience yourself from outside of yourself, that usually leads to Satan. Not to God, and I think all of us on this board want to know how to please God so that someday we will be with Him.