Indeed, a fairy tale
relationship in the beginning will keep you drunk with Love's ale
of happiness, but how would your relationship truly fare in the
looming cosmic lessons of love?
And it actually shows: in your first report card, it was an utterly
failure. This incident merely reveals to you that your relationship
is but some wax figure melting rapidly and horribly in face of
some heat emitted from the
monstrous machine of our cosmic lesson.
To feel even more disappointment; it wasn't even extreme
heat.
Your entire post did not mentioned any notable crisis or situation
leading to the downfall of the relationship and you are probably
puzzled at how insidious this decline has unknowingly degenerates
the relationship till the point of no return without you
understanding why.
Allow me to reframe your post and I will share my two cents through
this little story:
***
When Woman declared
her love to Man and pledged it as forever, at that magical moment
of time, it was true.
Then Doubt popped by and asked 'How do you know?'
'Don't ask me how I know, I just know,' Woman replied.
In a flash, Doubt faded away.
***
When Man had to
complete his conscription, in his absence, woman gazed at the other
scores of man around her.
Doubt appeared and asked "So do you know now?'
'I think so', she murmured
Doubt just stood there looking blankly at her.
***
Woman was with Doubt,
looking over the rice field from the cliff and saw Man harvesting
the rice alone.
Doubt pointed at you and said to her: 'You see that little D beside
him? That's my twin.'
'How come he seemed oblivion to little D's presence?'
'Oh no, you are mistaken - he can't see little D, only you can see
it.'
'Why is it so?' asked Woman.
'That's because I represent what I manifest - I appear whenever you
have doubts with yourself. Now, apart from yourself, you doubted
the Man you claimed to love forever, thus my twin will shadow him
whenever you plant your gaze at him.'
'Then how do I remove that away?' cried Woman.
'Let me ask you again: would you know now?'
'Perhaps... I only thought I knew...' she admitted.
***
You are a good man,
but a good man doesn't guarantee you a lasting relationship. In
fact, regardless of the position we are standing at, nothing
guarantees you an eternal love - it's all a matter of choice.
She has realized that at this current moment of life - she needs a
boyfriend, not yet a husband. From the journey before it reaches
that destination, a boyfriend is a role you must fulfill to keep
love alive. Surely, you are a nice guy, but your quality is ONLY
perfect when she has arrived at that destination, but not exactly
the journey towards that goal.
She tried to retain you emotionally, despite lacking the passion
for you and the relationship because in love, people are ten times
more fearful of regrets than rejection. She probably feared that
the kind of security you readily offered to her is unavailable
elsewhere and that might be lost forever if she has decided to give
it away.
Thank goodness, in that confused state of emotions, she has decided
to stick to her decision and not allow this fear to create more
complication.
Bestow her freedom - let her fly high and go.
If it was meant to be, it will be. 
Cheers
