Hello can you please upload your save file to us, you can see how in the link below:
https://community.sigames.com/bugtracker/instructions-and-notes/how-to-upload-files-to-us-r98/
Can we also ask, have you tried this again since the first instance? The servers might have just been temporary down when trying to join.
An additional thing to try would be to send the save to one of your friends so they become the host?