~snip~
To everyone else: learn from my mistake. If you've got substantial crypto, move it to your hard wallet immediately. Don't let overconfidence or negligence jeopardize your assets. It can happen to anyone, myself being a stark case in point.
For someone who does not understand the basics, even a hardware wallet will not help, because even such wallets are vulnerable when it comes to clipboard malware. It may be a sophisticated attack, but it is very likely that you have a compromised computer with a possible RAT (remote access trojan) installed.
For such a large sum, I would have definitely made a much better effort and checked everything at least ten times, but obviously everyone has their own standards when it comes to such things. The problem is that these standards sometimes come back like a boomerang and hit an inconvenient place, and then we find ourselves in a big problem.