I just felt the same when I relogged onto an old char and tested some stuff. I got wrecked. Then I realised I hat a complete passive reset. After respeccing my passives, I still felt that it was more difficult than before the patch.
But not as dramatic as you describe here. Maybe this is build dependant. Or there are bug that cause this but not for everybody equally.
I would expect there to be an overwhelming rant from all over the forum if there were such hard hitting global increases of difficulty.
Currently there are a few people that report these issues. Maybe its build related and a result of nerfs of specific skills/passives.
There are rants all over the forum - check the threads linked above, and some others in General and Feedback as well. This definitely isn’t an isolated feeling.
All of these mobs have already seen adjustments in the prior patch(es). If you are still having trouble, it’s either
1). a build issue where you aren’t doing enough dps or have enough defenses
2). a learn to play issue and learn how to dodge or kill them fast
3). a get good issue
Seriously, they are a joke now compared to how they were when released. I’ve played 2 new alts through the campaign since the nerfs and you rarely get multiple stacks of shock or poison unless you are standing still or training mobs.