Is there a point in Macbeth where the main character feels lonely—in the sense that no one understands his guilt?

In Shakespeare's Macbeth, I don't
believe Macbeth feels lonely because no one understands him, but I do believe that
towards the end, he feels isolated because he is alone, which I think is very different
from loneliness.

At the start of the play, Macbeth is an
honored warrior. His King loves him for all Macbeth has contributed to the war effort,
and promises to further reward him. Macbeth is close to Banquo, his friend and one of
his men-at-arms. When Macbeth returns home, we find that he and Lady Macbeth have a
strong bond as well. In terms of the kingdom, Macbeth also enjoys a reputation of valor
and strength.

This changes dramatically: he kills the King;
his peers become suspicious of him; he kills Banquo; and, he and Lady Macbeth become
very distant. (Whereas they had planned everything together, he has started to leave her
out of his schemes; ultimately,  she takes her own
life.)

By the time Lady Macbeth dies, there is no one
Macbeth can share his ideas or concerns with: his servants are fearful of him (for good
reason). All he can see is his obsessive need to hold onto his power. As his servant
Seton helps him dress for battle as Malcolm approaches, Macbeth's bravery is dampened by
his desperation, and perhaps an inkling that the witches have played him
false.

As Macbeth goes out to fight, we see a glimpse of he
noble warrior he once was: it's as if the madness that accompanied the witches'
predictions clears for a moment, and Macbeth decides to go out bravely, much the way the
former Thane of Cawdor, another traitor, went to his death at the beginning of the play.
At this point, he must fight this last battle alone, as even his soldiers have fled or
joined the other side. He is certainly alone.