Why cant Brutus fall asleep in act 4?

In Act 4 of Shakespeare's "Julius Caesar," Brutus struggles to fall asleep due to his overwhelming guilt and anxiety about the consequences of his actions. He is tormented by doubts regarding the assassination of Caesar and the subsequent turmoil in Rome. Additionally, the looming threat of conflict with Antony and Octavius weighs heavily on his mind, preventing him from finding peace. This inner turmoil reflects his moral conflict and the heavy burden of leadership he bears.