Did he die?? Or her dream means hes alive somewhere far

After everything I believe he ended his life, that's what it all pointed to (in my opinion). He kept saying all he had left to do was watch (his mother's death), he also stopped going to work, there was no fixing his tragic emotional state and all the damage his mother caused him, that was consistent the whole story. When his highschool crush has her vision of his happiness I think it was just wishful thinking on her part.