WHM learning curve for level 50 dungeons

Well let me start by saying I enjoy challenges on DF. In this case , Wanders Palace Hard, first time healing this yesterday and manage to keep everyone alive except me.
This was frustrating the group obviously because no one could rezz or had any Phoenix downs and had to wait to respawn at beginning. So I guess I wanted to know if the curve for healing is more difficult than say tanking which I like but not as challenging for me. Is there a better way mitigate cool downs for healing that will help keep me alive as well as everyone else?

thanks

Was it on the last boss? That's because there is a doom mechanic, where you can remove with almost any single-target heal. A Cure 2 on yourself is enough to get rid of it. But it's very easy to heal everyone else and forget about yourself and end up dying because of doom.

I echo miraidensestsu and think it was likely doom that got you if the issue was the last boss. The last boss has two main mechanics that are for the tank and healer. The first are the circle markers he places on the ground, which the tank needs to pull him out of. The second is doom. If you are already used to seeing debuffs with the blue bar above the icon that indicates the debuff can be cleansed, this version of doom does not have it. It cannot be cleansed, and the way that it is removed is by healing the inflicted party member to full. Pay attention to the status bars and you'll see a purple icon with a blue-ish black swirl on the inflicted player, which can be anyone in the party.

This particular dungeon and boss aren't necessarily a curve in difficulty for healing, but it will require for the healer to be paying more attention to status debuffs. For future reference, doom is a very common mechanic with voidsent type bosses. They can be some nasty buggers, so always keep an eye out for that icon when facing them.