What is happening to my Discus fish?

Hi, everyone!
I have been having these Discus fishes for nearly 45 days now and they always look stressed. The yellow one is bigger than the other 4 discus and keeps bullying.

Tank mates
Rainbow - 4
German Blue Rams - 3
Red Phantom Tetra - 3

Please take a look at the images and let me know what should I do to fix them. I'm getting stressed more than the fish now.
Thanks in advance

Go to the disease section of the forum and fill out the questionnaire. There is not enough information in your post to assist you.

Hello,
Sorry you are having issues with your discus.

Please use this form..

http://forum.simplydiscus.com/showth...lease-complete

You can copy and paste to this thread.

Thank,
Al