Sick Arowana

Hi guys, so it's been almost a month since my arowana eyes turned cloudy (looks yellow/purplish to me) and two weeks since it has eaten.

It was my late dad's fish so i really have no idea how to care for it properly and I'm also not sure what breed of arowana it is.

For 4 months I've only been changing the water every week (add salt and anti chlorine) and previously it had one side cloudy eye and i added more salt and it recovered.

Now both eyes are yellow/purple cloudy and it doesn't want to eat at all.
I usually feed it mealworms and it'll eat about 5-8 a day.
Tried giving frozen prawns it also don't want.

Today I come home and one of the back scales dropped (maybe it jumped and hit the light) and the left eye got a bit of blood, plus the skin near the mouth seems to be flaking.

Please help me on what I should do :-(

Thanks in advance!