Get 3 or 4 more. Then put them in a bigger tank after a month or two. . Don't be afraid! Just start reading as many threads on here as you can. It's all here. You just have to go through them. If you start asking basic questions off the get-go then you may or may not getting any replies. I think you will be just fine though since you've been keeping fish for a long time. You are doing the right thing with water changes. Just remember that discus like to be in groups.