I was in your boat for about a week OP.
What I ended up doing was making my own Titan run and inviting everyone who wanted to go, regardless of gear or experience. A straight up learning run, where nobody would get kicked out no matter how bad they might screw up.
A couple hours later we had broken the heart a few times and gotten some good practice at Phase 5. We parted ways without a win, but with a ton of experience.
Beating Titan goes in this progression:
>N00b: You screw up, eat landslides, and die to plumes every single time. (you'll spend 5 or 6 runs like this)
>Newb: You can dodge landslides, but still get hit by single plumes regularly. You're starting to get the pacing of the fight but still not acting fast enough. (you'll be here for 5 or 6 more runs)
>Average: You can dodge landslides and 80% of plumes. And you can avoid the first two bomb patterns. Maybe you kill the heart and maybe you don't. Lots of people stuck here (10-20 runs). This is where you find out if you need better gear or not. Most DF runs will stall here.
>Improved: You can dodge all the landslides and all the initial plumes. You know the first two bomb patterns by heart and can usually break Titan's heart, but you die early in Phase 5 to the huge plumes, new bomb pattern, and small arena. (5-10 runs) At this stage you're starting to really memorize how the fight goes.
>Skilled: You can handle everything up til Phase 5 without any trouble, and you're learning to move pre-emptively to keep the plumes out from under you and how to dodge the new bombs. You still get hit once in a while, but you can get Titan down to 30% or below with regularity. Sounds like you're here (5-6 more runs).
>Master: You can avoid it all. Plumes, Bombs, Landslides. Nothing touches you except Tumults unless you're having bad lag or get unlucky (boxed in by Landslide as bombs go off around you, say). If it were a solo fight you could ace it. This is where you'll end up with practice. You're here or almost here.
>Ragequit: Now you need seven other Masters to party with, and none of them can be lagging. (1-Infinity attempts). Pure dumb luck of the team that you join. This is what held me back from a win for so long (25+ attempts for me). And I went through the early stages a little faster than most. I probably killed him after 40 total attempts.
Titan sucks, but there's a definite feeling of accomplishment when you beat him. He is, as the Internets would say, "Nintendo Hard." If it weren't for him and maybe Hydra, getting a relic weapon would be trivially easy. Once your whole FC or LS has beaten him, going back and doing it again will get easier and easier until he IS trivial. I remember thinking when I first started him "This is BULLSHIT! Nobody could do this! It's WAY TOO HARD FFS!"
But he really isn't, looking back on it. Getting good enough, knowing your moves enough, and being able to predict his movements are important skills in the game. Clearing Titan legitly will absolutely make you a better player.
Don't give up OP.