Using textual evidence, why Septimus commits suicide, even as he thinks, “Life was good” (149)?

I thionk he thinks life prior to WW1 was good. He hears voices, namely of Evans, and becomes extremely sensitive to color and natural beauty. The doctors compound his problems by ignoring them, and they become the embodiment of evil and humanity, in his mind. When Dr. Holmes pushes into his home to see him, Septimus throws himself out the window to his death.