How to find the ender portal in minecraft?

I'm playing minecraft, which i downloaded to my 360. I know that to find the end portal, i have to throw up enderman eyes. I've continued doing this, following the eye from each direction and level of elevation and all thrown eyes, thrown from ANY place on the map, lead to the same location but there's no end portal in sight. Can someone please tell me I'm not losing my mind here?

It has been a very long time since I have played minecraft so I could be mistaken, but I believe the ender portal can be found buried underground with a bunch of other ruins. Just follow the ender eye and when it takes you to that area again, start digging straight underground and you should fall through to a room where the portal is contained.

Then go to where the Eyes lead you and dig down. The Portal is usually only a few blocks up from bedrock, hidden in what it known as a fortress. Dig stairs rather than straight down, you'll want to be able to go in and out.

There's no eyes of Ender in minecraft pe