You might look into things like
http://www.wowwiki.com/Line_of_sight and do some CC yourself.
But in general, as a healer, if somebody hurts you, you did something wrong. Its a lot about positioning.
You can learn most of it in the arena, but it also applies to Battlegrounds.
There are hundreds of instruction videos like this:
http://www.youtube.com/watch?v=rO3R-MNor-E
You can also run with friends, that peel the enemy off you, when you're under attack, while you're learning.
Also, you should not complain about the basic game mechanics, without some experience. It might be not as fun as you expected, but there are many ways to counter these mechanics.
And you should never pretent to be world class "top 5 in most games", as nobody will believe you anyways. Professional (top 10 - top 5) Players focus on one game at a time, maybe 2. Lying on the internet, expecially when talking about PVP, might net you lots of negative responses.
Just saying.