Hi and welcome to the forum
Most fish health issues are directly related to poor water quality caused by too much food going into the tank and inadequate biological filtration.
Get your water tested for ammonia, nitrite, nitrate & pH.
Do a 75% water change and gravel clean the substrate every day until we work out what is going on.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.
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Post pictures and video so we can see what is happening.
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.
If the video is too big for this website, post it on YouTube and copy & paste the link here. We can view it at YouTube. If you are using a mobile phone to take the video, have the phone horizontal so the video takes up the entire screen. If you have the phone vertical, you get video in the middle and black on either side.
The following link has information about what to do if your fish get sick. It's long and boring but worth knowing.
http://www.fishforums.net/threads/what-to-do-if-your-fish-gets-sick.450268/