2pac, for the following reasons (among others):
His mother was in prison when he was in her womb, and she rarely got enough nutrition there to keep him healthy (she had to file numerous petitions to get enough calories / nutrients)
He believed his father was dead until finally meeting him at the age of 23
He was a given a false name (Lesane Parish Crooks) at birth because his mother was worried he would be targeted because of her political activities
He was constantly moving as a kid / teenager, and frequently lived in homeless shelters with his mother and sister
His two biggest father figures were Legs, a small-time hoodlum, and Mutulu Shakur, his step-father who was a Black Panther. Legs ended up dying of a cocaine-related heart attack when Tupac was young and Mutulu went on the run and was eventually locked up for breaking Assata Shakur (Tupac's godmother and Mutulu's sister) out of prison, among other crimes
His mother was frequently in unhealthy relationships and was beaten in front of him
His mother abused cocaine / crack and was often "not there" for Tupac when he needed her
His family was extremely impoverished. They frequently had the power taken away from them in their rat and roach infested apartments in NY / Baltimore. The neighborhoods Tupac grew up in were dangerous / drug-infested. He also wore hand me down clothes that were tattered and ill-fitting. Kids at school made fun of him for his clothes and the fact that half his family was locked up in prison for Panther-related activities
Tupac excelled at the Baltimore School of the Arts but could not graduate from there because he did not have sufficient math credits and his mother moved he and his sister to Marin City, California so she could help appeal Geronimo Pratt's conviction.
When Tupac and his sister arrived in California alone (Afeni didn't have the money to make the trip with them at the time), the woman they were supposed to be living with had just checked into a mental hospital, leaving them with nowhere to live
Tupac had a number of friends of his die violently over the years, including a good friend he knew in Baltimore
Shortly after Afeni arrived in California, Tupac moved out because of her crack cocaine abuse and dropped out of school. He lived a transient life, bouncing from sofa to sofa in his friends' apartments / homes
Tupac often suffered from depression throughout his life and had an alcohol / marijuana dependency. Some of his friends saw him as an addict. He could not function or be happy most of the time unless he was drinking or smoking weed.
Tupac was assaulted by Oakland Police for jaywalking. He sued and eventually won a settlement
Once he became a rap star, Tupac was sued countless times for a myriad of claims. The legal fees he paid drained his bank accounts. Even when Tupac was a famous rap star, he was frequently broke and had to do shows / films/ guest appearances he didn't necessarily want to in order to pay his lawyers
Tupac was robbed, assaulted, and shot five times in New York's Quad Recording Studios after mouthing off to manager / drug trafficker Jimmy "Henchman" Rosemond. Tupac believed a number of people he considered his friends knew that the attack would take place in advance but didn't warn him.
Tupac spent 10.5 months in Rikers Island and the Clinton Correctional Facility for "sex abuse," a crime he vehemently denied committing. In addition to the shame of being stripped searched, having your freedom taken away, etc. while in prison, Tupac had to endure the embarrassment of rumors that he had been raped by an inmate there. Had he lived, it's likely Tupac would have had to return to prison if his appeal had been denied.
Tupac's family depended heavily upon his income and often took advantage of his generosity, running up extremely high bills for hotel stays and other luxuries. This increased the already extreme pressure on him to make money
Tupac died after being shot four times and then enduring the removal of one of his lungs and about six days of being in a coma.