How does Dimmesdale react the the truth that Chillingworth is Hester's husband and what does that say about chillingworths actions?

When Hester finallly tells Dimmesdale about
Chillingworth's true identity, Dimmesdale runs the gammot of human emotion. He initially
does not handle it well at all. When she first introduces the name of the man who is her
husband, Chapter 17 says, "Never was there a blacker or a fiercer frown than Hester now
encountered."

This angry posturing doesn't last long,
though. He soon falls to his knees on the forest floor, saying he should have known it
and felt it in his guts all along. He then follows this by blaming Hester for allowing
him to be in so much pain and in the clutches of the enemy for so long, just by keeping
her silence. This drives Hester near madness. She can handle anything but Dimmesdale's
disapproval. She holds the weakened, sickly man as a hug-hostage until he finally
forgives her.

Dimmesdale finally realizes that, although he
is plagued with guilt, he finally knows someone whose sins are worse than his own -
Chillingworth. He and Hester face their lowest low, but they face it
together.