What did my teammates mean by this

so we were very close to winning multiple times but we kept getting beat in payload defense overtime and i said that i hated overtime "overtime because you heal" "cuz your heal"

i was playing moira and healing the tank and the dps who would be near and i healed pretty often and got 21 kills as well by helping out the tank so im worried if i did something wrong? because the other healer and the tank were the ones that said this and I don't get it, i thought i played decently since i was active everywhere. (I'm new as well so sorry if it isn't obvious to me)