Satan is saying that the other angels do not know how much he regrets his rebellion. God wanted the angels to follow rules in heaven but Satan could not so he was banished. Now Satan is forced to adhere to God's punishment whether he wants to or not. Satan must spend eternity in Hell, he loses his angelic title, and he loses God's favor and grace. The word abide is ironic, because Satan has said all along that he does not want to submit to God's will but by abiding to his punishment he is doing just that. 

Satan also recognizes that his pride was false. His boasts were conceited and they have brought him down as well as many others. This is a typical ending for ambitious characters. In modern times we view ambition as a good quality, but during Milton's time ambition was looked at as a fault. Many of Shakespeare's plays deal with the fall of ambitious characters and Milton, being an early neo-classical writer, would want to follow in these traditions.

abide- to accept the consequences of; to submit 2. to behave in accordance with; adhere to rule.