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.