Hi, i'm a reeeeeally good sorc healer, pretty much unkillable. I laugh at people who try to 1v1 one me. But guess what happens when I come across a good team with 2-3 dps (usually depends on the classes, marauders especially mess me up) who know how to assist and how to burst? I explode in seconds.
Healers are by design inheritely team players. Of course your lone wolf mentality doesn't stand a chance against them. If we can't even keep ourselves alive, we can't do our job.
Oh, and I also play a sniper who drops most healers in seconds (decent geared mercs/troopers are an exception). But that's because they are bad or occupied.
Play smarter. Play better. Use teamwork.