Welcome to discus keeping . A)don’t believe anything on “All about discus”!! Probably the worst Facebook site. But fun to read and add comments .
Unfortunately you’ve been on there way too long. Just beginning your tank will not work. May work for a time and then you’ll have problems. 90% of beginners just start buying more and more discus. Then end up with a problem. A planted tank is not where you want to medicate fish. Next as you’ve already stated angels can be very aggressive. Yes you’ve heard already they’re great with discus on Aad. Not true. They will cause your discus to stress the stress will get them sick. The sickness will cause you to medicate.the meds will kill your plants and probably your discus.
Best to start another tank bare bottom 75g or better and take it slow and learn your discus like you learned your plants before you start mixing. They can work together but first you need to know discus as much as plants. Here’s a thread I’ve got running here on planted tanks.https://forum.simplydiscus.com/showt...ed-discus-tank. And a pic of my 18085699209-69A5-40DC-84B8-98121CA7C384.jpg.