I may be stupid. God knows it's likely.

I'm trying to begin uploads of the second issue of my comic, DREAMNASIUM, but when I try, the system tells me the name is already taken.

I don't want to tack this story onto the end of the last one because they aren't related in any way. DREAMNASIUM is an anthology. Each issue is separate and distinct from the others.

What am i doing wrong?

you cant make 2 comics with the same name. try making the next one
DREAMNASIUM: secondary name
or something like that. actually having seperate comics for each issue hurts your ranking. keeping them in the same comic will let people read all your pages when they find your comic and thus increasing your rank. seperating them makes you compete against yourself. you could always divide them into chapters.

Thanks I'll do that.