The pasted message suggests you still have the "notes" file open in another Vim session. It is definitely not a good idea to edit a file that is being edited elsewhere.
If that message is wrong, you need to determine how your Vim session exited improperly and avoid that in the future.
As for recovering, that may be an issue in this one instance since "notes" is newer than the Vim .swp file associated with it, but you can still try. Just make sure you copy your "notes" file to a backup location first.
It would be a good idea to read through ":help recover.txt".
The lesson here is that you're not supposed to be seeing this message, and that you are means Something Went Wrong Somewhere. It's (probably) not the fault of Vim.
If at this point you are still absolutely determined not to let Vim create .swp files so you can recover from crashes and other related issues, you may put "set noswapfile" in ~/.vimrc.