Can’t best ITM?

I just tried ITM and died on the first boss when he had about 1,000 health left. I was manually eating whales, had Diamond Luck IV potions and using Piety and Battleheart prayers and using dragon/minotaur synergy. My setup is the attached image. I don’t know what else I can actually improve?

I have 99 skills in all combat (minus slayer) and my agility courses are: 1) Cargo Net 2) Monkey Bars 3) Pipe Balance 4) Mud Crawl 5) Cliff Balance 6) Lake Swim 7) Spike Trap 8) Raft Building 9) Ice Jump 10) Ocean Rafting

The only thing I can think of is maybe maxing out the combat astrologies, but is that reslly what’s required? Was I just eating at the wrong times?

Any advice is appreciated.