Coriolanus is certainly proud - he has a lot to be proud of - but proud he is. It is as if Shakespeare is illustrating the 'Pride comes before a fall' saying.
An interesting take is here:
http://www.drbilllong.com/Coriolanus/Pride.html (not saying it's a good essay - just interesting take). I like the self-deception element.
Also worth thinking about is Plutarch on Coriolanus: "Antipater, in a letter written upon the death of Aristotle the philosopher, observes, "Amongst his other gifts he had that of persuasiveness," and the absence of this in the character of Marcius(Coriolanus) made all his great actions and noble qualities unacceptable to those whom they benefited: pride, and self-will, the consort, as Plato calls it, of solitude, made him insufferable. "
The idea of his pride not isolating him from others (that's his inability to communicate) but making him insufferable to those he has issolated.
And a final quote:
"According to the Church, and thus to Western man, the most deadly sins are these. Violations involving them may be great (mortal) or small (venial).
Despair Hatred
Vanity Greed
Anger Gluttony
and of course Pride.
In one point of view at least, all these are variations on Pride. Judas's sin of Despair, for example, was in maintaining that his sin was so great that even God could not forgive it, which furthermore presumes that God's power is limited."
Coriolanus is not an ordinary man - and his pride is not ordinary!
(Good luck with the exam)