Are you spec'd heal? If that's the role you went for, then throw some heals out before the match starts so that people know, or announce in chat "<--- heals" or something like that. If you are really lucky, you'll get a good tank to, well, "tank" for you, and the rest of your team will watch out for you too. If you are only somewhat lucky you'll get one or the other. If you are in a standard PUG, you'll probably get neither, but at least that's no worse than where you are now.
And if the other team is paying attention - yes, they will gun for you. If you are not already doing this, basically try to hide. Find a spot where tunnel-vision-DPS are not likely to notice you and throw your heals from there. But a good team, as I typed above, will hunt you down, so I guess learn to kite? And if five of them are focusing you as soon as you spawn, just take comfort from knowing that you are such a threat that they need to devote that many resources to neutralizing you. Just keep telling yourself that.
Also do some searches here for threads about "how to heal" type things. There were some fairly good general discussion a while ago that probably still apply in 2.0. Hopefully you can find them. Or someone who knows more about healing than me will chime in with better advice.