Something weird happened now. In some mysterious way the btc I sent to Electrum got back to where I sent them from...

I shall try to re-send them to my Electrum wallet again.
Was it not maybe 'pending' and rejected due to a fee that was too low? You can try again but make sure that you include a fee appropriate to the transactions otherwise it might get stuck as 'pending' again, if that was the problem.
I don't know how low is too low? I'm new to this. But now the status says it's been payed but the date says pending and that it's unconfirmed. Perhaps I shall wait a bit?