This is the best description of my malaise:

Loneliness of Spirit:
Deeper than the Reach of Love
by James Park

Loneliness is an aching void in the center of our beings,
a deep longing to love and be loved,
to be fully known and accepted by at least one other person.
It is a hollow, haunting sound sweeping thru our depths,
chilling our bones and causing us to shiver.

Is there a person, anywhere,
who has never felt the stab of loneliness,
who has never experienced
the eerie distance of isolation and separation,
who has never suffered the pain of rejection or the loss of love?

The final rupture or breakdown of a valued loving relationship,
the sudden death of someone who was close and special,
an unavoidable separation from a loved one
—these things strike loneliness into our hearts,
the intense experience of the absence of that specific person.

Besides longing for a specific person,
sometimes loneliness has no name attached.
This is the general feeling of being alone,
isolated, separated from others.

And there is a third kind of loneliness—existential loneliness—
which is even deeper and more pervasive than either of the first two.
It often disguises itself as longing for a specific person
or pretends to be yearning for contact with anyone,
but this deeper lack or emptiness-of-being
is not really a kind of loneliness at all.

Being together with other people, even people we intensely love,
does not overcome this deep incompleteness of being.
This inner default of selfhood has never been solved by relationships,
no matter how good and close and warm our relationships might be.