Hi KevinM
I'm glad I bugged you for the answers because as it turns out, you have some major problem going on there. But at least now that we know what caused the problem, we can help you resolve it. I believe your cory has a bacterial infection caused by the a variety of stressful things that are going on in your tank.
First, did you mean to say your water is 32 degrees C.? That's almost 90 degrees F., which is way way to hot! This alone is a major stress to the fish.

Please start bringing it down
slowly to 75 degrees F. or 24 degrees C. This temperature will slow the growth of the harmful bacteria living in there now and is in a safer range than what you have. You can adjust it to the optimum temperature for your specific fish once this problem has passed.
Second, if there is aggression going on, either from the sharks or the gouramis, or even if your corys sense that they are around aggressive fish, it will effect them. This is another thing that might have made your cory ill.
Third, there is a good chance that your tank is not completely cycled, or that the additional fish you put in was just too much for your beneficial bacteria to handle. Without regular water changes and cleaning, harmful bacteria will grow as well as beneficial bacteria. There is a good possibility that you have ammonia or nitrites in the water.
Please test your water or have it tested at the lfs immediately. You will need to get medicine, so get your test kits or your water test done while you are at it. This will help us determine if you will need to get rid of some fish immediately or if you have some time to figure out what you will do for the long run. Perhaps you will be able to set up another tank before your fish get too much bigger.
How big is your current tank, BTW?
One thing for sure is that you will need to start doing some big water changes very soon, but how much will depend on your test readings.