it often is easier to lay the blame on someone. or maybe not easier, necessarily, but simpler. if there isn't someone to blame, things get much more complex. usually the case is that things are complex though. you may have to work through how you feel about his death again. you may feel worse for a while, but hopefully you'll come through to the other side, and be better off for it.
do you want to try to have a relationship with your aunt? it could start off very limited until you have a better feel for how it would go... this may be an opportunity to really expand the people who care about you...