You can follow along here for ESU
https://support.microsoft.com/en-us/topic/procedure-to-continue-receiving-security-updates-after-extended-support-ends-on-january-14-2020-48c59204-fe67-3f42-84fc-c3c3145ff28e
In my opinion you should restore from a backup, then migrate to a newer supported operating system.
--please don't forget to upvote and Accept as answer if the reply is helpful--

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