To prevent it fraying further get it close to a flame,
crush it as soon as it starts melting.
I would leave it outside ,
as you have no access to anchor the cord to the seam.
Tie 2 succesives knots at the end of the cord,
tie to fat grey seam,
through the knots.
I would avoid sewing the cord:
it's elastic and the thread isn't.
Use a little piece of cloth as a gorge blocking/hiding the knots,
and preventing chafing to your gracious neck.
To prevent it fraying further get it close to a flame,
crush it as soon as it starts melting.
I would leave it outside ,
as you have no access to anchor the cord to the seam.
Tie 2 succesives knots at the end of the cord,
tie to fat grey seam,
through the knots.
I would avoid sewing the cord:
it's elastic and the thread isn't.
Use a little piece of cloth as a gorge blocking/hiding the knots,
and preventing chafing to your gracious neck.