Tactician mode help Apostle of Myrkul fight

I am on phase 2 of the fight since i can use the speech check to get pass the first phase in the Mind player colony, I have tried multiple times now and it getting to the point where it's not fun at all, I am using all of the spells that give you extra actions and spells that stop your characters dying after a final blow hit and using potions that help attack rolls and resistance ones as well but it feels like i am not doing any damage at all to the boss at times since i might only get few attacks to hit the boss while rest are missing each turn and Dame Aylin just keeps getting killed in all of the times i have tried, I am playing as a custom character and i have reclass my character plus party members as well but i am still having a hard time doing the fight where i know i am not going to beat it and when i get to the boss area my character is close to being level 8 while the rest of my party is level 8 for the fight or this playthrough for bladur's gate 3 tactician mode a failure ? I am wanting to beat it on tactician mode and i am playing this on PS5