For Willy, the main feeling regarding his kids, his own life, and his reason to live is dissappointment. He was dissappointed at himself for cheating and being found out by Biff. Equally, Biff was disappointed by what his Dad did, and by what his Dad had become (a delirious man stuck in the past).
Willy also became disappointed seeing Biff transform from a Football star to a na'e doer, as well as his other son, Happy. He also could not forgive the fact that he had let life slip through his fingers, losing everything he had tried so hard to achieve.
Happy, who is literally a "happy go lucky" kind of dude, simply went along with the farce, and was just as fed up with the situation of Biff, his mother being such a martyr and a victim of his father, and of his father's condition. But, much like Willy, he is also irresponsible about his actions, and much like Biff, he is also trying to recapture something they used to have and now is gone forever which is their American Dream.
Lastly, as all dwell in all that is gone, each is just a mirror of each other's failures and for this reason, they are loveless, careless, and clueless. All of them are a piece on each other's puzzle, and none of them can change a thing about it.
When Willy commits suicide, it would maybe show how he wanted to break the chain of disappointment and misery that all of this highly dysfunctional family caused each other. He thought that it was the only way to end all the vicious cycle and perhaps start over, without the main instigator who was none other than Willy Loman himself.
In order to write about the three male's feelings from the play Death of a Salesman you need to list them first.
Willy Lowman is a proud father, lives in a dream world, can not face reality, sees what he wants in his sons instead of the truth, loves his sons, wants to give his sons the "American Dream", and hangs onto the idea that his son Biff will make it big.
Happy Lowman is the son who loves his father and wants to get his attention, is most like his father because he can not face the truth about his own role as an employee, wants peace in the home, has trouble growing up and being committed, still lives with his parents.
Biff Lowman has deep rooted anger at his father because he had cheated on his mother, is a thief and a liar, has been arrested, is nothing like his father wants him to be, and has just realized that he loves his father, but it is time to grow up and face reality.
Looking at these facts, how do you believe that each person feels about the other person?