I play, but I haven't finished the new quest lines yet. I'd recommend asking on one of the discords about it and maybe checking to see if your build is optimized for the fight.
Nukes & Dragons <--- excellent for build advice.
Edit: Just did the fight. I died 4-5 times but got it done in the end. He seems to regen to full health a few times, not sure why. After I managed to get all the adds down and take him down to a sliver of health, he stayed down. I'd recommend the scaly skin mutation and, if you're not using energy weapons, the grounded mutation. Stacking energy resist will almost certainly help.