Tips for defeating Brain of Cthulhu?

I’m playing on Revengeance Master difficulty and I’ve been struggling with him. My loadout consists of the Sulphurous set, Contaminated bite, all 3 horseshoe balloons, lightning boots, shield of Cthulhu and Fungal Clump (yes, I need all of those items for mobility). My total defence is 28.

In addition to that, I also have a question about the boss. I see him regaining randomly health throughout the battle, can he do that?