# You are saying this

"This is what you have said"

# Our transgressions and our sins are on us

Possible meanings are: they feel guilty for their transgressions and sins or they realize that Yahweh is punishing them for their transgressions and sins.

# we are rotting away in them

"they are destroying us" or "they are killing us"

# in them

"because of them"

# How can we live?

"We have no hope of living." or "We will certainly die"