I get that you're frustrated because you had really bad luck and it cost you a weekend but Titania isn't overtuned.
Most of the mechanics are self-explanatory: you see an aoe marker, you get your butt out of there. You see various circles appear, you stand in the last one spawning and move to the safe zone as soon as the first blew up, which everyone has already seen during the Shiva and Tsukuyomi trial. The one with the stack up marker should stand in a puddle but even if that fails, decent healers can heal through such a fail because it's not a wipe. It's a ton of unneccessary damage but managable.
The only thing that needs to be done correctly is that everyone switches to whacking the adds the moment they spawn and that can be softened by using LB on them.
When I did it for story progression dps was definitely on the low side and we had a lot of people failing at the aoes so both my co healer and I spent the majority of our time healing with barely time to dps but we passed the dps check.
All Titania requires is for 8 people to not be semi-afk. There only 3 things aside from the usualy dodging people need to do: stand in the puddle with the marker, switch to adds asap, move to the safe zone during frost rune.
You can even eat one hit from the frost rune and survive (unless you've already been really low), it's just running around like a headless chicken that gets you killed.
I'm not saying it's faceroll-level: MSQ Ifrit. But it IS perfectly doable for a full group of 73s with level-appropriate gear and without relying on healer dps.