What is the meaning of "Hasha Mimeni"?
Rashi: Slacken Your hand from striking me.
Malbim: Make the affliction depart from me. It is not proper to afflict him for his sins, since the body's nature leans to sin. The powers of the Nefesh that Hashem put in him to stand against the body, cannot stand against the strength of the great Giborim, ancient residents of the land.
What is the meaning of "v'Avligah"?
Rashi: I will be strengthened [Radak - from my illness, and return to do Your will].
Malbim: I will strive to strengthen myself over the lust and Yetzer ha'Ra before I go and I am not.
To where will he go?
Radak: To the grave.
Why did he say "v'Eineni"?
Radak: After I go to the grave, I will not be able to do Your will. Only this world is for action; the world to come is only for reward - "Ki Ein Ma'aseh v'Cheshbon v'Da'as v'Chachmah bi'She'ol Asher Atah Holech Shamah" (Koheles 9:10). "Asher Anochi Metzavecha ha'Yom La'asosam" (Devarim 7:11) - today (this world) is the time to do Mitzvos, and tomorrow (the world to come) is to receive the reward (Eruvin 22a).
Malbim: Via the poverty and afflictions that prevent me from perfection, it is as if I am not, for I will not fix what I must perfect for my eternal existence and happiness.