Im sorry but I did not realize you wanted to talk about mental health theories like structural dissociation theory.

in your original post you asked....

"If one suspects DID or DDNOS how does one go about determining what to do next without a local professional to help?"

many people when they are self diagnosing and researching end up self diagnosing with non existent mental disorders because they are not aware that the mental disorder they are thinking they have no longer exists.

I dont advocate for self diagnosing but since you may not have access to a treatment provider right now due to covid 19 rules and such I thought you might want to know that around the world there is no longer any mental disorder called DDNOS.

in your research of self diagnosing self treating, you may continue to find that disorder name because they dont take into consideration that things have changed in 2013.

DDNOS name was no more in 2013.
DDNOS name was changed in 2018
the new official name for DDNOS now is Other Mental Disorder - no disorder no condition.

they are both the same thing - that a person has symptoms and problems but not a mental disorder.

if you think you have DDNOS then you are self diagnosing / self treating
yourself with having no disorder no conditions.

if you are self diagnosing self treating for DID then you think you do have a mental disorder.

as for the structural dissociation I personally do not discuss theories online simply because some locations deal with diagnostic critera/ disorder names and other locations deal in theories which can lead to debates and fights, which .....many website forums..... have in recent years made rules against fighting and debating online to deal with facts in terms of diagnostics, not treatment theories.

good luck to you and please consider contacting a treatment provider and getting officially diagnosed as soon as things start opening up in your area .