Black Moor freaking out

[Ragnar]

SO,
I had my fish for 4 months and being a student I didn't pay much attention to him for the past two weeks. He has always been really active and competitive (i had a guppy in the same tank he used to steal his food all the time) I started noticing two days ago that he was freaking out and swimming everywhere for no reason. He stopped eating, hurt himself multiple times overnight until i moved him in a separate empty tank. Beside missing a few scales because of that he looks healthy and the only different thing that is noticeble is a little reddot on his eye and tinyblack dots under his belly (that has always beel mostly or completely white for what i remember. He doesn't eat or poop, has this ''panic attacks'' every 5 minutes constantly all day. I did some research and i think it might be a parassiteso yesterday i put some salt and garlic to help him mixed wth a natural general remedy (supposed to kill ichs,chilodonella, costia, trichodina, oodinium). He is just getting worst and having hard time swimming and balancing himself. I put an airstone in the tank and he just floats succking air and lets himself go until the next attack.
Any idea what is going on...? I don't wan't to loose my fish, I'm not giving up on him.

 

[Delapool]

Have you done a water test for ammonia / ph, etc? That could also cause this.

 

[Ragnar]

No I didn't but the new tank I put him in is brand new with new water and everything so I doubt ammonia would be the cause... He has been there for 4 days and he still doesn't eat, looks sad and barely swimms, just floating

 

[Delapool]

I’d do a water test or get the shop to do it ASAP. It’s the first check and I’d really recommend it just in case.

I’m assuming when you say brand-new, the tank filter was cycled? Or was this from 4 months back. How large is tank.

I’d make sure tank, water, etc is all fine first. Parasites sounds unlikely unless you have added anything in the last week. This might be more environmental.