Do we have any word to describe the situation wherein you lose interest in life not due to tragedies but boredom and you want to quit life because nothing mundane or spiritual brings joy to you?
a feeling of listlessness and dissatisfaction arising from a lack of occupation or excitement.
In psychology, the specific symptom of depression that you describe is anhedonia.
Anhedonia is the inability to feel pleasure. It's a common symptom of depression as well as other mental health disorders.
The link has more specifics.
world-weary(adj.) or world-weariness(noun)
Tired of or bored with life, often with a negative or jaded attitude.
American Heritage Dictionary
Feeling or indicating feelings of weariness, boredom, or cynicism as a result of long experience of life.
Oxford Living Dictionaries
feeling or showing fatigue from or boredom with the life of the world and especially material pleasures
no longer finding pleasure in living; tired of the world
The Germans always have the best words in such cases (here in a literary context)
Weltschmerz, (German: “world grief”) the prevailing mood of melancholy and pessimism associated with the poets of the Romantic era that arose from their refusal or inability to adjust to those realities of the world that they saw as destructive of their right to subjectivity and personal freedom—a phenomenon thought to typify Romanticism.
By the way, Schmerz can be translated as "pain", so "world pain" is a direct translation.
You could be describing acedia or accedie.
A host of psychological symptoms can signify the presence of acedia, which affects the mental state and behavior of the afflicted. Some commonly reported psychological signs revolve around a lack of attention to daily tasks and an overall dissatisfaction with life. The best-known of the psychological signs of acedia is tedium, boredom or general laziness.
Anomie. It refers to a failure of the external “norms” that guide a person’s life, as opposed to their internal emotional or intellectual state.
You are without joy, for example, because the actions that you previously took to achieve a joyful state are no longer working. Your spiritual practice does not bring you to an emotional state of transcendence.
At the same time, there is still the possibility that other actions or other practices might succeed. You have failed, perhaps, but it’s not just you. The people around you that should be providing the norms for you to follow have also failed. Or perhaps the failure is one of connection as opposed to a failure of individuals.
Anomie is not a commonly used word. However, that can be an advantage, since better-known terms like apathy or ennui tend to come with meanings already established in the reader’s mind.