Ever since I updated to the newest version on my S5 a month ago I've been annoyed by the new notification bar, the bar used to be out of the way and was only as big as the black bar up top. The new bar is annoyingly big, it's always popping up over text I'm trying to read and I keep accidentally pressing the notification bar when I'm trying to navigate my phone. Is there a way to go back to the old bar?
Looks like you are disturbed with Heads Up (new feature) notifications.
It will show a pop up notification on your screen. You can turn it off by Upgrading to any custom ROM or you can use HeadsOff app.
Which looks like a workaround for turn off Heads Up notifications.
I haven't tried this yet. But please take a look.
What you're talking about sounds like "Heads Up". This is a new Android feature that shows notifications easier. You can't turn this off unless you have Android M. But you shouldn't have Android M because the S5 doesn't get this update. The only other option is to run a custom ROM such as cyanogenmod.