Prayers for him and his family... for you I wish and hope that you learn and it seams you have, you don't need our opinions, but seems you feel guilty for hating so hard on him..
People can be difficult.. what you take from this relationship and experience is don't hate, it only kills you inside and keeps you from those that can and would help you.. perhaps in this case saving his life, but probably not..
there is nothing you could have done to help him, his small world was such that he could never let anyone help him and thus limited his life experience..
good luck..