Despair is something common to most of us humans. Now and again, we all, or nearly all, get that sinking feeling that something we hoped for is lost. It can make us irritable; it can make us angry; it can make us depressed; it can even make us anxious... but loss is like that:the human body will often do anything but face loss head on, and just accept it. We push, we pull, we act out... anything to get away from us, as quickly as possible, the feeling of loss. We even sometimes create little battles we know we can win, so as to reduce the impact of the battles we have lost.
But despair teaches us a lesson, if we want to hear it. It teaches us that there is something we have been hanging on to, whether it's an ambition, a relationship, a possession, a state of mind or being even. The despair would not be there if we had not had a hope in the first place. Without hope, despair can't happen.
So, logically, it would be true to say that the existence of despair tells us that we have, yet again, been hoping for things, in a world which is almost assured to disappoint. If we despair when someone dies, then our feeling shows us we have been pretending to ourselves that death doesn't happen, that we are somehow protected from it. If we despair when we lose money or possessions, then it shows us that we have been pretending that those possessions were part of us, that we needed them to truly be ourselves. If we despair at the end of a relationship, then it shows us we have been hoping that the relationship would be with us for ever, and would protect us from unhappiness.
It is a certainty that everything we have will be taken away from us: our bodies, our possessions... everything. Attachment to things, material things,is something bred into us by millions of years of evolution: the ones who were not sufficiently attached to their parents, or food, or their homes, let them go and did not survive. The ones who fought for their relationships, their food source, their territory, perhaps survived. But they, too, in the fulness of time, will lose everything, because the end happens eventually. That's how our bit of the material universe seems to be built. We are like fireworks: we fly for a while, and then we run out of fuel, and crash to earth.
In meditation, we can contemplate this, and, ironically, gain some happiness from the thought. If we can face, head-on, the fact that everything we have will be taken away from us, and really accept it with our deepest mind; if we can learn to be calm, in the firm understanding that there is nothing material that lasts; if we can learn to let everything go as easily as it came... then it does bring a particular kind of happiness. Partly because we understand that to be here, now, seeing what we see, and experiencing what we experience, is a little miracle in its own right. OK, we die, but while we fly, we are fireworks.
We may feel guilty, that we can feel unchained to loss, and be happy when people die. But this would be to misunderstand the source of the happiness. The happiness comes from a deep understanding of the nature of things, and death's place in the nature of things. We can still aim to remove suffering from people and other beings who are still here, stuck in the world, if we want to. So there need be no guilt. To reconcile oneself to death is not the same as wishing death on others. Accepting loss is not the same as causing loss. We can still be as helpful as we want, even if we accept losses when they happen.
So listen when you despair. What you will hear is a part of you that is not yet reconciled to loss. Be kind to it. But at the same time, try to allow that part of you to see that loss is everywhere. Every moment of every day, someone, somewhere, is dying. Why are you not in constant despair at this? Because you are not attached to the others, the ones not so close to you. To have someone dear to you is to expose yourself to loss... unless you can accept that endearment may be lost at a moment's notice. If you can learn the art of living constantly with the threat of imminent loss, then, ironically, you will get used to it, and it will cease to be a threat.
So, in short, if you find yourself despairing, look for the hope in which the despair originated. I guarantee there is something you are clinging on to that is causing that despair. The hope that people live for ever; the hope that we are always protected; the hope of continuity. When you have found the hope, then you have found an unrealistic thought. Contemplate its unreality for long enough, and you will find that you were hoping irationally for something that never was. When you accept the irrationality of hope, then you will accept the irrationality of despair. When you have rejected both, then you can live in complete acceptance. It may not guarantee you a longer life, but it could easily alleviate your suffering - because suffering depends on irrational hope, and fades away altogether where there is complete acceptance.