taking down Titan as tank

[Ashkendor]

Titan story mode? As long as you're not losing hate and you're utilizing your cooldowns you're doing it right. Have you cross-classed Convalescence at all? It's a good cooldown that you should already have access to. Step 1: pull with Tomahawk and face him North. Step 2: Endure the beating from the fat man in the loincloth.

What exactly is happening to cause failures?

Looking at your Lodestone info, your accessories are desperately in need of some TLC. Some of them are caster accessories (they give int and mind bonuses), some are bard/ninja accessories (they give dex), and some are simply outdated (level 15-19). Look for some accessories with vitality or strength on them. At the level you're at, you could either use sphene (vitality) or sunstone (strength). Silver accessories would also work.

[Eye_Gore]

I'm thinking I could use Second Wind or anything similar to help replenish my HP, as well as healer help.

While in a party you shouldn't have to worry about healing yourself so much. While it can help, especially if the healer is having trouble, but I wouldn't worry too much about it. The healer shouldn't have much of an issue keeping you alive, unless they're dead of course.

Endure the beating from the fat man in the loincloth.

Hey now, he's just big boned.