Your tank water looks milky cloudy and this is normally caused by uneaten food breaking down in the water. The fish laying on its side and not acting normally is also an indication something is wrong and most of the time it is poor water quality.
Test your water for ammonia, nitrite, nitrate and pH.
Do a 75% water change and gravel clean the substrate every day for 2 weeks.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.
How often and how do you clean the filter?
The following link has information about what to do if your fish get sick. It's long and boring but worth a read when you have some spare time.
If your fish ever looks sick or unwell, then the following steps might help. Test the Water and Clean the Tank. Test the water quality for ammonia, nitrite, nitrate and pH and write the results down in numbers. Check it for general hardness (GH) and carbonate hardness (KH) too if you can, but...
www.fishforums.net