Do I need to restart? Stuck on Ch2 Boss

Thought I had played FFT back in the day but now realizing all my experience was FFTA2. Didn't realize how to learn skills until around lvl8 and didn't figure out how to equip skills until around lvl 13 (im silly I know). Was attempting the castle and boss fight with a party between 14-16 and got crushed. Forced to grind until party was between lvl 18-19 and am still failing. Party consists of the following: Ramza (knight-monk), Agrias (holy knight), 1 orator-white mage, 2 knight-monks. Trying to use purification but it rarely gets rid of doom status. Did I need a few members to have items (phoenix down-remedy)? I can get to the third dialog set pretty easy but I just keep missing with revive cast and purification. Any tips would be appreciated?