Mr. Healer man as everyone else has stated, it is not you, it is the stupid dps/tank at fault. Stop healing them...if they kick you, oh well, let them wait for a replacement...eventually youll get a group that is good. I do a ton of tanking and healing in this game, and I have found that I no longer care about stupid ppl, as a tank if you are a retard i will kick you, if the kick does not go through, i will just leave. They can either follow a proper kill order, or wait on a new tank/healer. I wish I could say itll get better, but you run into a lot more of these tunnel visioners in hms lol