Stuck - need help getting Blood of Ch'thon

I’m at level 60 and apart from bounties, the only quest I have is to complete the Bastion of Chaos to get the obsidian shard - I’m assuming this will open up more quests. I’ve tried everywhere appropriate for my level on several sessions and I cannot get anything that I can turn into a Skeleton Key (Blood of Ch’thon, Ancient Heart, Tainted Brain Matter). Has anyone got any advice on where to find this stuff at level 60? I really feel like the drop rate has decreased in a massive way with the new update, make it almost impossible to enjoy the game when you’re grinding and getting no results time after time.

Try looking for a treasure trove. There are some fairly easy ones to find in arkovian undercity, the first 3 floors of SoT and the first area of bastion of chaos.

Nine’s suggestion is good, those are easy to get and troves drop purple mats at least 80% of the time probably a bit more?

Drop rate was not changed in the patch and as someone who no lifes this game it doesn’t feel any different to me. Note that enemies significantly below your level won’t drop them, but that shouldn’t be an issue unless you are moving back to a previous difficulty

Blood: bastion, ashen wastes, obsidian throne. bastion is best since there is a easily accessed trove too and it’s quick
Brains: Lower crossing->burial cave spam farming the reanimator boss Kyzogg is easy way to get brains. Warden runs are good too
Hearts: Croplands->royal hive is solid with a lot of gtd heroes and two bosses who will drop them at a high frequency. Twin falls port running up to the hive is good too, normally a few bug heroes and a gtd boss

Such troves are also in the Chthonic Void. In addition you also have a good chance to get Blood of Ch’thon from the heroes there.