WAIT WAIT WAIT stop this!
you know, I'm in the same server I'm a main healer, never had a complain.
They could be more sympathetic and polite, but I'm sure 99% is your fault.
This game has its own rules, you cannot "spam heal" and think "i'm doing fine". You aren't.
My advice is "begin from level 1" as conjurer -> whm or arcanist -> scholar and understand every skill
Another good advice is "try to play as tank or melee dps", you will see how others play the healing class.
P.S. I play healer in WoW, in Lotro, in RIFT... everyone is different.