Let me explain why:

She's locked in a cage full of hurt right now.

Her life as is - is pretty damned chaotic.

If it is as crazy as you depicted, then she's
got a lot of shit to sort out. And you may or
may not be involved. That choice should be
yours, not hers.

So it was right of you to confront her about it.

But if you wanted it to be right for her, (or at
least avoided the ending of her blocking you)
then a little better timing would have helped
you a great deal.

But what's done is done. Lets focus on your situation.

So here's my observation:

1. She has no control over her problems at work at
the moment. Until she finds out a way to sort things out,
she'll always be stuck in the predicament she's always
trapped in. Believe me, for as long as she stays that way,
you probably don't want to go be involved with her.

I'm not even surprised if her real life is as shit as her
work life. She seems like one of those people who just
keeps bending and bending until she breaks and after that,
she just turns hostile to the entire world because nobody
can sort her shit out.

Because she can't sort her shit out.

Don't get me wrong though; I'm not saying you shouldn't
date people with issues - I mean, everyone has their own
set of issues. Me included.

But that battle she has is something she needs to fight on
her own. You can cheer her on and give her your full support
but aside from that, there's really nothing much you can do.

Kindness from others can't solve her problem right now.

An act of courage from her own heart will.

Let me give you a real example:
You could probably be her secret admirer and buy her
chocolate daily. She can feel a little happier everyday,
knowing that someone out there cares about her well-being,
but in the end of the day, the chocolate just feeds her soul;
it doesn't actually help her sort out her problems.

I donno, I guess one can remain indefinitely hopeful that she
would be able to become braver with enough happiness.

Give yourself 3 years. Who knows. *shrugs*

So if you really like her, and you understand what you're
getting yourself into, then, sure. Go ahead and throw
yourself into her mess. You're gonna be stressed like hell
with her everyday problems. But if you're ready to share
her burdens, make sure you don't ever let her down.

You breaking up with her then will just cause her to be
suicidal - and you probably donwanna be the trigger to
her end.

2. You're not the trigger of her stress. But if you are,
and you know that for a fact, then she probably saw
you as more than a friend. Either way, it wasn't right
for her to take it out on you. It's okay to care for
someone. But just because you do doesn't give her
the right to make you a human punching bag.

Going around the fact the she did see you as more than
a friend - then her outrage might be caused by you being
too dense about things. Maybe she started developing
expectations out of you and when you don't deliver them,
she gets really irate.

This happens a lot when the guy doesn't know the girl
likes her, and the girl REALLY likes him.

Think this way -  her life is already pretty shit right now,
and she's been into this guy for almost a year, and when
he can't understand her enough to even take a few hits,
she'll probably get really offended.

Offended enough to break a friendship?

Probably.

3. Regardless of whether she forgives you or not, you
should still be nice to her to the best of your abilities.

Tell you what - the next time you see her or bump into her,
do whatever you can to grab her attention for a moment.

Then just tell her this:
"Look, I know you don't feel like forgiving me. And honestly
I don't really care about that anymore.

I just want you to know that regardless of how you feel right
now about me, I'm still your friend. And I will do whatever I
can to help you if you let me."

If the moment is right, and she starts showing signs of opening
up to you, then you might be able to slip in your feelings along.

Only if you're ready though. She seems like a problem to big
for you to carry. You're young and you're still doing your own
stuff. I also have a feeling that you don't have as many enemies
as she does.

Are you really considering rocking the boat for her?

If you love her, and being with her makes you happier than
anything else in the world, then go for it.

But if you'e uncertain; have no conviction, I'll advise you to steer
clear for your sake, and for her sake.

Maybe the distance that you have now is for the best.

4. If you want to help sort her problem out, there's a way:
a. Find out why her department leader is backstabbing her.
b. Is she being backstabbed because of her character or
her working ability?
c. Do you know her as a competent human being?
d. How is her character like in front of others?
e. How is her life outside of work?

After all this questions, then only you can ask the question:
f. why can't she do x y z for a b c?
g. why can't she just quit the job if it saddens her so much?