mmm your not having a fun time with discus are you? did you research them or just impulsly buy them m8? by the sounds of your tank its not really cycled yet as you still have ammonia being produced.
i can tell you for fungus get something like pimafix.
as for the ammonia readings still being there... if i were you m8 id take the discus back to the store and wait until your tank reads 0 ammonia, 0 nitrite(which i noticed you havent posted a reading for) and 0-20 nitrate.
i really love these fish and ill be starting a discus tnak befor christmas. i couldnt bare loosing one and i think youll probably end up loosing the 2 youve posted about if you dont get them back to the store. i may be wrong and your reading may be due to some other reason but if its showing ammonia they may die. id rather take them back and know theyve lived then to see them die and loose 100$+ each fish.
my thoughts on the matter.
everything else like ph u seem to have gotten right though. try some beef heart ive heard, duno but yeah. id take em back and fully establish the tank. maybe keep some other fish like angels or SD's until ur sure the tank is right.
ill be setting a tank up next week which most probably will be a discus tank in the future, after i get my saltwater tank stocked (cycling starts tommorrow YEY). ill be establishing the discus tank then when alls good ill be keeping 3 XL-L silver dollars for 5 months in there befor ill be sure its discus ready. then they can go back into their 12" their currently in
.