Lonely
The likely word is the adjective or adverb "alone" (by oneself, solitary).Of similar spelling is the word lawn, a grassy yard.
The word for not being able to explain oneself is "inarticulate" or "incoherent."
Pride.
Adaptability and flexibility means being able to adjust oneself to different conditions.
The root word for "lonely" is "lone" which means 'being alone or solitary'.
It is an adjective. It can be used as a noun, as in "He was in solitary", but the full version of that is "He was in solitary confinement". So the noun is being left out as the sentence is abbreviated, turning the adjective into a noun.
No, the word "lone" is not a verb. It is primarily used as an adjective to describe being alone or solitary.
more depressed, most depressed
Perfectionism is the word used to describe being too hard on oneself, setting excessively high standards, and being overly self-critical.
a solitary man sat on the hill.
My friend and I were playing solitary games.
The word that means proud of oneself is "self-congratulatory."