Death comes with a flood of different and sometimes conflicting emotions. One of the most difficult of these is anger.
Anger in some form is a nearly universal response to loss, and when we lose a person we love, there is no shortage of things to be angry about. We might be angry at God for letting us suffer, angry at the person who died, for leaving us alone with unfinished business and children to raise, angry at a relative for something they did or didn't do, angry at ourselves for what we did and didn't do, angry about our new status of orphan or widow, angry at the insensitive platitudes heaped upon us by well meaning, but clueless friends, or angry about the seemingly endless details, tasks, changes and costs that must be looked after.
Sometimes anger at the situation we find ourselves in can be directed at someone we have other issues with, or someone who just happens to be in our path at the wrong time. In any case, whether the person or the situation we are angry at is really to blame for our anger or not, the anger is real and needs to be acknowledged and dealt with. Of course, dealing with our anger at a hectic and emotionally sensitive and demanding time is a challenge. Add to this, the fact that many family gatherings can be contentious during happy times, let alone following a death.
Determining the real cause of the anger is a good starting point. I would also advise talking and venting with a trusted friend. What you don't want to do is lash out and complicate an already difficult and tender situation. In most cases, anger is resolved if confronted honestly, but be prepared to accept some ambiguity. There are some questions that we can never know the answers to, and some conflicts that can never be amicably resolved. Ultimately our task is to move forward through life, and we cannot do that if we are crippled with anger. If thinking, talking and venting do not allow your feelings to be released sufficiently, don't push your feelings aside, seek the guidance of your clergy or a professional counsellor.