There are two
parts to this:
I) You are right in saying that
her reason for break up is merely a reason to diss you off. And if
you haven't realize by now - any reason will suffice actually.
After all, words are just words - the content isn't as important as
the intention.
In the other side of this
context: if a person genuinely wants to remain in a relationship,
even for the wrong reason, she will stay. Nothing can make her
leave if she is bends on remaining.
You cannot force Love upon
another just because you desire it so - much more than the
willingness for a person to be with you.
II) If you are determined to
change your flaws, it must be a revolution from within and not some
feeble method to 'win her back'. The latter is often a short term
measure to rebrand your identity, but since the core hardly
changes, you will probably revert back once the 'inflated
initiative boost' wears off.
People often talk, very
superficially, about how they will change in name of Love, but I
can tell you most merely end up diverting these negativities into
other section of emotions or energy and not learning to resolve
them through higher/spiritual understanding.
If your ability to evolve is
largely depended on the existence of others and their approval,
then you will lead a life where your growth is limited by the kind
of people that live in your environment.
Sometimes in Love, one must learn
to release before one can learn to walk forward. 
Cheers
there is the 3rd part, THE CHUCK NORRIS WAY!