1)
What is the meaning of "Tzaros Levavi Hirchivu"?
1.
Radak: Afflictions widened their residence in my heart. This is a poetic way of saying that they are many. Therefore I scream to You!
2.
Malbim: I give to no importance to all worldly matters. I do not heed worldly afflictions. Just the contrary - they expanded me, and I rejoice in them!
2)
What is the request "mi'Metzukosai Hotzi'eni"?
1.
Radak: If my heart is trapped in afflictions, it is not free to serve You!
2.
Malbim: Remove me from difficulties of the inner Nefesh, for they cease my Avodah.