Why did Kurt Cobain commit suicide?

did you ever see .....Courtney Love ?

Advocates of the verdict of death by self-inflicted gunshot wound have cited Cobain's persistent drug addiction, clinical depression, and handwritten suicide note as conclusive proof. Members of Cobain's family also noticed patterns of depression and instability in Cobain before he achieved fame. Cobain mentioned that the stomach pains from an undiagnosed stomach condition were so severe during Nirvana's 1991 European tour that he became suicidal and stated that taking heroin was "[his] choice"; saying, "This [heroin] is the only thing that's saving me from shooting myself right now."] Cobain's cousin Beverly, a nurse, stated that the singer's family had a history of suicide, and that Cobain's bipolar disorder and his struggles with drug addiction led him to suicide.

In Charles Cross's biography Heavier Than Heaven, Nirvana band member and bass guitarist Krist Novoselic is quoted on seeing Cobain in the days before his intervention: "He was really quiet. He was just estranged from all of his relationships. He wasn't connecting with anybody." Novoselic's offer to buy a nice dinner for Cobain resulted in unintentionally driving him to score heroin: "His dealer was right there. He wanted to get messed up into oblivion ... He wanted to die, that's what he wanted to do

He was on drugs and mentally ill.

from what i read he was very messed up and in the head too.

He was using too much drugs

Too much pressure on him as the best rock singer ever in that time after his masterpiece album 3 years before his suicide, and the other theory is Kurt Cobain was heavily on drug and killed him.

well he didn't