# I heard

You may indicate what it is that Habakkuk heard. Possible meanings are 1) "I heard everything in that vision" or 2) "I heard Yahweh approach like a great storm" 

# my inner parts trembled

"my heart beat rapidly" or "my stomach turned" 

# My lips quivered at the sound

Quivering lips is another spontaneous response that comes with great fear.

# Decay comes into my bones

"My body goes limp, as if my bones were rotting"

# under myself I tremble

The words "under myself" refer to what is below him. Possible meanings for the idiom are 1) "my legs tremble" or 2) "I tremble where I stand."