Try to make a list of your achievements. In addition to the fact that recently shook your ability to enjoy life, you probably have a million other reasons to live happily.
More often dream about how you would live well, if you did not have circumstances that had weakened you.
And then continue to live just as well, simply ignoring your circumstances.
Remove from your lexicon such words as "hopeless grief", "doomed to misfortune," "not created for happiness."
You, for certain, know the stories of "rich and famous" who experience exactly such feelings. Money and fame - not a guarantee of happiness, although very diversify life. The main thing is the angle at which you perceive your life, your achievements and your chances for the future. Change the angle - and see your happiness.
It is important to doubt your doom for suffering, the inescapability of your woeful state. We doubted for a little while that your depression will not last forever - this is a big victory!
According to Socrates, the most important principle of knowledge is doubt ("I know that I do not know anything"). Doubt encourages a person to self-knowledge.
So doubt it! Doubt that you are doomed to misfortune! Place more signs of questions along that rutted rut where your sorrow rolls, convincing you that this is the only possible way!
And then give specific answers to the question, what in your life can still cause admiration and even envy among others. Let it be something insignificant, such as the unique color of your eyes or the ability to cook patties, or to fish, or to pick mushrooms. There is no doubt that you have both talents and circumstances that anyone will envy. Well! And you all black paint in a row smeared. For a layer of this blackness you can not, but rather, do not want to see a grain of the good that, of course, in your life there.
And you try to put your current problems on one cup of the scales, and on the other - some kind of oncologic diagnosis. Well, are not you ashamed? Let us not angry fate, which can at any time give us something really terrible. As they say, stop roaring, or I'll give you an excuse for tears!
No loss of a husband or work can be closely compared with health problems. But in the sphere of health, one should not despair. It is necessary to fight! There is simply no other way. To win in the struggle for one's health, one should perceive his diagnosis as a signal from the bugler, announcing the beginning of the battle. Well, if you do not have health problems, but your relatives, then you should fight with redoubled energy!
Are you planning to enjoy yourself and enjoy your depressed state? Please, it's not safe - you can get carried away. You will wear the robes of a martyr, you will not have time to look back, as the years of life flew by.
So, the idea that one should not mourn for lost happiness is already the first germ of a reasonable attitude toward grief. Happiness in this way still can not be returned, but the remaining life itself can be dashed easily.

Ask yourself the following questions:
Is it possible to push the limiters and live differently?
How to get out of the cage into which you yourself have been imprisoned voluntarily?
Is it possible to compare the scale of your current grief with the importance that you will then attach to your present circumstances in the future?
Is it possible that the concrete concrete impact of fate is the first step in growing up and comprehending the wisdom of life?
Are there old people around you that have survived a lot of losses, but have carried a positive attitude through your whole life?
Maybe it's time to stop opposing yourself to those around, who sincerely wants to distract you?
Maybe, on the contrary, try to force yourself to participate in what is happening around you? Let in the beginning through force, but the organism will recollect "normal" reactions of the healthy person - will recollect how to laugh at a joke or an absurd situation.
Try to "try on" yourself this new, free from grief condition gradually ..
Today existed only 5 minutes, breaking out of the chains of depression, and tomorrow try to stretch this period for 10 minutes.
Gradually narrow the black spot of your grief on the perception screen of the world. Narrow it to a tiny point. Then the colored mosaic of the surrounding world will return to your life again, flooding the sad darkness with its bright colors.
It is important to stop looking into the narrow funnel of grief! It is necessary to expand your horizon, narrowed by grief, by willpower. Why not just try out of curiosity? Try it! After all, there is still nothing to lose.
And what happens? After all, you are deliberately distancing yourself from the rest of the world. You build a wall, separating yourself from everyone, raising your sorrow high above all this fussy world.

You are experiencing a whole range of emotions, including the desire for suicide and other experiences of depression. Just do not get carried away with your own inimitability. There is nothing unique in your state. We, the anthropomorphous Homo sapiens, have a similarly similar physiology. Depression is a typical enough nervous reaction to stress or trauma. It is similar to the situation when you picked up salmonella in some bad restaurant, with all the "consequences" that result from it. Anyone who is infected with depression passes through the same and typical stages of the state until he recovers, and this must inevitably happen. Only some people start taking medicine to fight this disease, while others deliberately prolong the unpleasant condition, getting stuck in it like a person suffering from diarrhea, gets stuck in the toilet for a long time.
You should look at what is around you, at all the good and positive things that you are just blocking, simply refusing to see. After all, happiness is an attitude toward life. Happiness is not even a fortune. It's harmony and balance. Look at the world with fresh approach - a gaze enlightened by tears - and you will begin to appreciate all that you still have!