Alright @eris thanks for replying. Can we take a step back:
here is mentioned to keep the subdomain seperate in the admin account from the main domain.
What i think of doing now, is abandon digital ocean nameservers, change mydomain.com dns with the registrar, where i set my glue records for nameservers and A record. Than simply leave as if. I’ll use 2 dedicated ip’s for the glue records. This seems like the best way to me or am i missing something?