Saul Bellow's novella, Seize the Day, was originally printed in a collection that also contained two short stories and a play. The novella quickly earned the reputation of a piece of literature that could stand alone, receiving strong critical acclaim. It is the story of Tommy Whilhelm who argues with his disapproving father (as they live in the same building—the Hotel Gloriana) is "needy;" besides feeling separated from his parent, he experiences "alienation from [himself] and from humanity," including his family: his dad and sister, and his wife and two sons.
With regard to adjectives that describe Tommy, there are quite a few that would be appropriate, including:
Middle-aged, overweight, slovenly, out of work...
Tommy might be seen as argumentative, a poor decision-maker, unfaithful (he has had a mistress, Olive), sad (he misses his sons badly), insecure (as he looks for "his father's approval and some kindness"). He is self-conscious, especially about money (he is only steps away from "financial ruin"). He is emotional, irrational, and lonely.