Again, is the address you posted from Circle or from Electrum?
No darnit I don't. It looks like my electrum wallet has never been used. There's no history, no invoice, there's nothing. I have no idea what I did. Is it hopeless? Did I really just lose 300 dollars?
Before everything disappeared it did have unconfirmed and pending next to it, if that matters at all??
Yes, it does matter. It means that the transaction could have dropped from the network. It also means that the transaction could have confirmed. Right now, we don't know.