Thank youWell, Welcome to the wonderful world of salt water !
That said you've started learning the painful wisdom that experience yields and books & the internet often gloss over.
My son went through much the same with his first tank, luckily it was less expensive fresh water. However, the conclusions were the same :
A. The first fish in often establish territory and "bully" latter occupants into lesser desired territory.
B. Characteristics of a species or a class of fish are not reflected in all. Sometimes there is a anti-social psychopath among the "community fish."
C. As for humans, "Time Outs" are not always effective.
D. Tantrums happen. A for legged pet may destroy the couch when left at home, and a unhappy child may throw some toys. Fish find ways to express their displeasure too.
Much like the rest of our lives, one must take a moment to decompress, develop a plan, and then return with steely resolve.
You may feel defeated now; however, I assure you that years down the road you will see this as a decisive moment. Just keep moving ahead.
Best wishes in the fishes,
Jim, who has committed every possible error at least once