What is the meaning of "v'Ha'achalti Es Monaayich Es Besaram"?
Rashi: I will feed Chayas ha'Sadeh the flesh of the Bavliyim. Monaayich is like "Al Tonu" (Vayikra 25:14) - Ona'as Devarim; they vex you with their insults.
Radak: Monaayich are those who forcibly oppress you, like "v'Lo Yonu Od Nesi'ai Es Ami" (Yechezkel 45:8). The Targum is v'Lo Yenisun (they will not steal). I will make them eat their flesh. This is like "Ish Besar Zero'o Yochelu" (9:19).
Malbim: Those who used to verbally afflict you until now, saying that your hope is lost, they will eat the flesh of those who contest you, i.e. they will fight with them.
What is "che'Asis"?
Radak: Wine of grapes or [juice] of pomegranates is called so, for it comes via squeezing and crushing. This is like "v'Asosem Resha'im" (Mal'achi 3:21).
Why does it say "Damam Yishkarun"?
Rashi citing Targum Yonasan: Those who normally drink blood, i.e. birds, will be 'inebriated' from [drinking so much of] their blood. Radak - it is as if it says mi'Damam.
Why does it say "Ani Hashem Moshi'ech"?
Radak: I save you above nature, with the power of Hashem, who has the ability.
Why does it say "v'Go'alech Avir Yakov"?
Malbim: I will do this due to the connection that I have with Yakov, and via his virtue.