Help! Red Patch On Fish Belly.

[pink_beryl]

My flower horn fish has an unusual red patch on its lower belly. I'm not quite sure whether it is internally bleeding or what... My fish is floating upside down and this infected area can be clearly seen out of water. My fish is also unable to swim back right side up for now. It is also less active than the usual. What is wrong with my fish??? I dare not feed it anything for now as I fear something even worse might happen... Is there any treatment available for my fish?

 

[WILDER]

Can we take a look at your water stats in ammonia,, nitrite, nitrate, and ph.
Septicemia hard to cure once it advanced.
If the fish is floating upside down sadly is dying, so sorry.