A person that both deeply wounded the writer, and also had great influence on him too. How being around that person has "infected" him, possibly leaving misdial effects from their abuse/distructive ways. "Gravity claiming all your tears" could either mean the person committed suicide by jumping, or how tears fall heavily and often with this person. "Everything looks so much better now" really made me think that the person did kill themselves, and now the writer is left with all of the emotional mess.