To what degree do we DEPEND on others ?

Is it truly possible to be AUTONOMOUS ?
to rely ONLY on oneself ?
How much do we actually NEED others ?
What do we need others for ?
Can a person exist as a LONE ENTITY ?
Is that even possible ?
Why would one WANT to live in such a manner ?
OR...
Is it not a CHOICE ?
but rather,
a SENTENCE of sorts ?
a PUNISHMENT ?
FOR WHAT ?
What could one possibly have done to deserve
UTTER SOLITUDE ?
In Jewish Law,
 there is a notion of a consummate punishment called
 'KARETH'...
It means, literally, "to be CUT OFF"....
It is interpretted by our sages as the potentially LETHAL SYNDROME of
 "being cut off from YOUR OWN PEOPLE in the World to Come"...
a GRUESOME and  HORRIFYING consideration...
It is a punishment which is believed to be rendered in the most HEINOUS of situations.....
as a result of CLEAR, DISOBEDIENT  NEGLECT of certain, extreme commandments....
So...
my question is this :
When does  SOLITUDE become UNLIVABLE ???
UNMANAGEABLE ?
Is it, in fact, SELF INFLICTED ?
How does one break free of the ultimate chain of 'utter detachment'....
Chew on that for awhile....