David sure must have had his share of problems.
This is another Psalm in a long line of many that consist of David pleading for God to rouse Himself and fight against David's enemies. In this case, David begins by lobbing some rhetorical questions at God that reveal he is, if not exactly angry, at least peeved at God.
How long, God? Will you forget me forever? How long shall my enemy be exalted over me?
David then reminds God that he is but a mortal man, and so this is a limited-time offer. If God doesn't act and David dies, David's enemies will be victorious.
At least the Psalm ends on a confident, faithful note as David realizes the object of his faith is sure to not let him down.
Lest you think that I am too hard on David, let me confess that I've had my share of moments of frustration and impatience with God also. I guess I'm just lucky I didn't write a Psalm every time!