• 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.

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