How can you live through guilt? How can you again befriend with those who may
hold you at contempt? How can you trust others without lossing
your self-respect?

My personal opinion is that the only true way to overcome guilt is to
be truly sorry for whatever it is that you are guilty of.  As for
befriending those who may hold you in contempt, a truly heartfelt
apology is the best you can do.  Hopefully, those who truly know you
will forgive you for whatever it is, though this often takes time.

I answered a similar question last year. This might be helpful to you:

http://answers.google.com/answers/threadview?id=242338

I think everybody deals with guilt at some point in his/her life.  We
are human and imperfect.  However, when we screw up big time, there
are three things we must always do:

1. Apologize.
2. Repair the damage.
3. Put it behind you.

First we apologize.  This is to start the healing process for all
involved.  It may sound completely useless but it is vital.  Second,
we must repair the damage.  If we broke something, we must pay for it.
 If we are lying, we must confess.  If it cannot be repaired, we must
ask what we can do otherwise.  Only after completing the first two
steps can you accomplish the third, moving on.  Bringing it up again
dwells on the pain and does no one any good.  Learn from it and spread
the knowledge gained.

Just like this is a process, the person or persons you harmed are
going through their own process of shock, anger, sadness and remorse. 
It is up to them if the friendship will continue.  That you cannot
control.   The fastest way to return to normality is to start the
process.  Good Luck.