The original question had to be edited. It is difficult to think of Tom as having a conflict. He is the force of negation in the novel and there does not seem to be much with which he struggles in light of a conflict. Yet, I think that one conflict, or issue, with which all Daisy, Tom, and Myrtle, represent is how to reconcile their emotionally callous behavior with people who have the curse of loving them.
This is not a conflict for Tom, but it is a source of tension within his characterization. Tom shows nothing but disdain and brutality, both physical and emotional, for the people who happen to care for him. He shows disrespect to Myrtle, who happens to have feelings for him, and he shows the same type of disregard for marriage and children with how he treats Daisy. In the end, even though he and her leave together, one gets the distinct impression that they will not be emotionally together. In the final analysis, Tom's mistreatment of those who are cursed to care for him and how he displays emotion to these individuals is a shared conflict with Daisy and Myrtle.
The way that Tom is dismissive to Myrtle is the same way that she treats her husband. Myrtle's conflict is that she loves Tom and she shows nothing but contempt for her husband, George. She looks at him "the way one would look at a ghost" and constantly berates him in front of others. The emotional callousness that Tom shows to Myrtle is something she mirrors in her treatment of George. It is interesting to note how Fitzgerald shows that victims of abuse replicate the same abuse to others. The dehumanization that happens to them is what they perpetrate on others. Certainly, this becomes a part of Myrtle's characterization. Like Tom, the conflict that is brought out is how she treats those, in this case, George, who have the curse of caring for her.
Daisy mistreats Gatsby in a similar manner of disregard that Tom and Myrtle treat the people who are condemned to care for them. Daisy cannot bring herself to stand by Gatsby. Even though there is nothing but honor in the way he treats her and, conceivably, he would never harm her in the way that Tom harms her, she abandons him in his time of need. The emotionally empty way in which she treats him is reflective of how callous Daisy is to one who loves her. Like Myrtle and Tom, the conflict that helps to define her characterization is the fundamental mistreatment of someone who loves her. In this, Fitzgerald seems to be making a statement that some of the worst behavior that human beings can display happens towards people who care about us. It is here in which conflict presents itself, reflecting on one hand an acknowledgement of those who love us and, on the other hand, a statement of how we mistreat those who are cursed to love us.
In the middle of the novel, Daisy runs over Myrtle with her car and this creates a conflict between Daisy, Myrtle, Tom, and even Wilson. This event, in essence, ties everyone together. Tom claims to be upset over Myrtle's death and over consoling Daisy. Wilson, grief stricken by his wife's death seeks out the man she was having affair with and incorrectly assumes its Gatsby. This prompts him to kill Gatsby. One single action creates a chain of events that ties all the characters together.