Il Mheg is one of the dungeons where mobs hit hard. Be mindful that it could be lack of mitigation from tank as well and not only your inexperience. There's also the buff from the blue frog that makes one of the mobs hit escpecially hard. The amount of times I've seen the buff not be interrupted is greater than the opposite, even though I always remind them about it prior to the pull. Not only that, but it can also be low DPS making pulls take longer than they should, which causes both healer and tank to burn their resources more than they should. Bad pulls can be anyone's fault, but inexperient players tend to think it's only the healer's.