Sharing info as mentioned above by SaraB...
I would start by doing a couple back to back 30% pwc to help get that water cleaned up. Vacuuming the substrate the next day or later that evening would make a 3rd pwc.
When you did treatments, did you remove carbon, or Purigen, or other chemical media in the tank?
If these spots look like Ich. White spots all over the fish like the pics of spots on the fish in this thread
https://www.aquariumadvice.com/freshwater-ich-yuck/
https://www.aquariumadvice.com/ich-ick-white-spot-or-whatever-else-you-call-it/
A few pics would be helpful as well.
How long has the tank been running for?
Do you have any scaleless fish or Cories, or Inverts like shrimp or snails in the tank?
Getting the water parameters in a safe zone is hugely important to possibly saving the fish. Unsafe water causes their body more stress and makes them more sensitive to strong antibiotics as well as their diseases.
Treating the Ich with salt and heat takes days up to 2 weeks because the Ich has different life stages and you need to get them all.
The pics would help. At this point medication might be the fastest option but also the most stressful method. Of course dying before gentler meds can take effect also isn't the best either.
All the treatments might not have been for long enough period of time to kill off the Ich.
If you have an air bubbler I would add that asap. Or if you have hang on the back/ HOB filter you can reduce the water level a few inches for more splash/ aeration.
Do you use Prime water conditioner or other water conditioner which neutralizes ammonia, nitrite and nitrate?
