Hi and welcome to the forum
Can you post a picture of the fish?
If the pictures are too big for the website, set the camera's resolution to its lowest setting and take some more. The lower resolution will make the images smaller and they should fit on this website. Check the pictures on your pc and find a couple that are clear and show the problem, and post them here. Make sure you turn the camera's resolution back up after you have taken the pics otherwise all your pictures will be small.
------------------------
Elephant nose, eels, loaches and catfish are commonly referred to as scaleless fishes because they don't have scales over their body. This makes them more sensitive to chemicals in the water. If you have to treat scaleless fish with medications, you should check the medication and see if it is safe for scaleless fish. If you can't find a medication for scaleless fish, you can use a normal medication at half strength.
Having said that, whitespot can be treated just by raising the water temperature to 30C (86F) and keeping it there for 2 weeks. However, post pictures of the fish so we can confirm if it is actually whitespot or something else.
If you have to use medications, make sure you work out how much water is in the actual aquarium. Many tanks are sold as x gallons but they hold less water when there is gravel ornaments in them.
Before treating any tank you should use the following formula to work out how much water is in your tank, and do the following things.
To work out tank volume:
measure length x width x height in cm.
divide by 1000.
= volume in litres.
When you measure the height, measure from the top of the substrate to the top of the water level.
There is a calculator/ converter in the "How To Tips" at the top of this page that will let you convert litres to gallons if you need it.
Remove carbon from the filter before treating or it will adsorb the medication and stop it working.
Wipe the inside of the glass down with a clean fish sponge.
Do a 75% water change and gravel clean the substrate. The water changes and gravel cleaning will reduce the number of disease organisms in the water and provide a cleaner environment for the fish to recover in.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.
Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it. Wash filter materials/ media in a bucket of tank water.
------------------------
The following link has information about what to do if your fish get sick. It's long and boring but worth knowing. I recommend printing it out and reading it in bed to help fall asleep
https://www.fishforums.net/threads/what-to-do-if-your-fish-gets-sick.450268/