How do I get my bitcoins back if they got sent to an incorrect address?
You appear to have caught some malware that replaces Bitcoin your addresses with their own when copy-pasting one. You'll probably want to look into removing the malware from your computer.

Meanwhile, it is unlikely that you'll be able to recover your bitcoins. The Bitcoin network doesn't have a way of reverting payments. Basically, you're in a similar situation as if you handed cash to a different person than the one who was supposed to get it. Unless you can figure out who it was that got it, there is no way to get it back. There is no central registry of Bitcoin users, and as a general rule you cannot identify users from addresses alone.