1)
What is the connection of the two halves of the verse?
1.
Radak: Because our Nefesh waits for (hopes to) Hashem, He is our help and shield.
2.
Malbim: Even though their hope does not come immediately - my bones rotted (31:11), and our Nefesh waited many days - He was our help and shield. He helped us from the hunger, and shielded us from the afflicter.