I created a character, leveld him up and then learned I could copy over characters. I then copied my characters over and now my old character I made is gone. Can I get him back, or am I fucked?

Seems as if when you copied characters over the server deleted the created one

when you copy your live account.. thats what you get, your live account at last snapshot.

everything you have or had is erased and what you end up with is an exact copy of your live server account.

if you copy today you will get what you have today. if you copy again tomorrow you will not have what you worked on today on PTR only what you have tomorrow on live

so after you merge when you go back play regular. you wont see the items you got while playing on ptr?