Sorry you went through that. While the suggestions to record self and improve and all that are good, I feel like it's worth mentioning...
Even if you play completely perfectly, this is part of the healer experience. Sometimes I can show someone a death report that breaks down exactly what they did wrong by each fraction of a second, and I still get cussed out. The best you can do is try to surround yourself with people that aren't toxic for preformed-party content, but sometimes in DF content it still just happens, unfortunately.