Stuck on the Chapter 4 Titan fight, debating restarting the game to better prepare

So yesterday and today I spent I think about 7 hours unsuccessfully trying to beat the Titan, closest I got was making it a few rounds into the 3rd attack cycle at which point someone inevitably goes down, I can’t brighten and thus inevitably am overwhelmed by the Titan Spawn or fish.

My current playthrough, I have realized (the hard way) I’ve been pretty neglectful of equipment/weapon upgrades-didn’t get any noticeable TP boosting equipment or stronger weapons, I think I’m using the same stuff I was using at the end of Chapter 1. I’m used to kind of brute forcing my way through RPGs but I’m not sure if that’s viable here.

I was already considering at some point in the future replaying to maximize content (in this playthrough I didn’t fight Jevil, Spamton or Gerson for instance and would like to save Tenna if I can), so I’m debating whether I should keep at it with the Titan on this current save or start a new save and hopefully enter better prepared later on.

Any tips on avoiding attacks would also be welcome, I’m on a PC.