This is not really an error; it's more a matter of style.
Is it not? I don't think I've ever seen a double semicolon before.
It's fine. It would be much better with a conjunction (or separated into at least two sentences), but c'est la vie.
OP, it's not going to keep you out of a school. But it's pretty nutty. And I speak as a semicolon devotee (easiest, fastest way to fix a comma splice!).