Yagluth rant

I just want to complain. I beat yagluth solo, first try without any issues when the game first released. And then life happened, and me and my wife had to wait for 2 years to fight him, it took us weeks and a fuling genocide to find him and after we find we just got wiped, always.
Both full padded armor, frostners, bonemass and fire resist, and still, didn't even made a dent. I've beaten Elden Ring, and was less frustrated there. The fight just takes forever, and once bonemass runs out (and yagluth is down to 95% health) at least 5 fulings, deathsquitos and a herd of loxes spawn near him.
We used the altar as cover, but first he shot one of the pillars down, then a horde of loxes joined the fun and shredded the other pillars, so there's no cover.
Today I beat him solo, because my wife was too frustrated to try again, and only because his animation froze on the 50th attempt to kill him and I spent 3 minutes just hitting him non-stop until he finally died. (Switched to blackmetal sword, levelled from 0 to 21, which tells you how bizarre his healthbar is)
Am I just stupid, or is his balancing completely out of line with the rest of the bosses?

Suggestions to improve him:
– LESS HP!
– Less spawns of mobs around his altar.
– Some sort of firearmor? Vikings had asbestos, right?