This will hurt your brain!

Yes and gravity would begin to work against you

You would burn in the earth's core :3

well if you dont die in the core, when you reach the inner mantle of the other side, gravity will be flipped and you would be pushing yourself up each ring, going hundreds of thousands of miles like this is impossible, so you will either die from exhaustion or you decide to flip so it is easier, so unless you are superman, you will either die or come out right side up,