I couldn't be more pissed ...

It's an informal expression meaning 'angry. The BrE equivalent is '****** off''. Many people consider these expressions to be rather vulgar..

''Story of My Life is definitely my favorite One Direction song of all time, and I couldn't be more ****** I can't buy it right now.''

After careful perusal, I want to ask one more question.

If someone says that X is defiinetely his or her favourite Y song of all time, why oh why he or she says that he or she gets irritated and can't buy that music?

He's angry because he can't buy the song right now.

He is saying he is angry BECAUSE he/she can't buy his/her favorite song.

story of my life, when a person says that they could also say in it's place. This is how things work out for me every time. It's often used when a person hasn't succeeded in what ever they were attempting, such buying a song, they can't ever get the one they want. That's my understanding and it's an expression a range of emotions depending on the person and their tone it may be one of many such a

"Story of My Life" is his favorite song by the band, One Direction, and he is angry because he can't buy it immediately.

a DJ said that its" story of my knife"
as he was making this parody

In America, ****** does not mean drunk. It means angry.

"One Direction" is the name of an English-Irish pop boy band, and "Story of My Life" is a hit song that they made. It's also your friends favorite song. Your friend wants to purchase the song but is very angry that he/she cant right now.