A lot of people on here will probably tell you to:
Step 1: Read all of the sticky threads in the beginners section of this forumn.
Step 2: It looks like you have something swimming around in that tank....get rid of it and start with a fresh cycle...STRONGLY consider going bare bottom with no plants. You might know plants but you dont know discus so its not a good place to start.
Step 3: Buy all you discus at once, if you cant afford it just dont do it, because cross contamination is a big deal.
I'm sure you will get plenty more good input but thats something to chew on for awhile. A lot of people fail hard with discus and you've got a few of the common denominators going on.