Just about everything you have figured out, was figured out by someone else before you. By people who died long before you were born.
You’re not experiencing something new. You’re repeating the past experiences of others. Some of the details are different, that’s all.
I don’t believe in reincarnation, in terms of souls living on in new bodies, but we are re-experiencing things that others have experienced. And we’re connected to all people, living and dead, in a mysterious way.