I am curious to know as well, since I have not come across many things pertaining to online subspace.
I get confused as well between the subspace and subdrop.
Subspace I can handle, and can get feelings of overwhelming euphoria, but with my situation, I am left alone with it, and eventually I am left with subdrop that may occur right away or days later. I get into a horrible funk.

I have since learned that a proper mindset of the sub is good to have, with proper diet, and exercise, subspace and drop can be dealt with better.

After any play online, setting aside some time to discuss feelings or even just talking about anything would probably help the sub come back down easier.

Even immediately afterwards, sending short reasurring notes, and continuing to do so even days later would probably be helpful.

I am only going by my own experiences on thiis.