Irrational despair

What is the word I'm looking for?
What feeling am I trying to name?
Why should an outer appearance I give,
Make me feel I am somehow to blame?

I should be feeling on top of the world,
Like I could fly to the moon,
Yet the higher you climb, the further you fall,
And life still plays the same tune.

After months of meticulous planning,
It fell in to place like it was meant to be,
But somehow now it's all over and done,
It seems nothing more than a dream, you see.

Filling in my time, planning my dream,
Took everything I had to give,
And now I feel so empty and low,
I almost wonder how to live.

For looking at the memories we have,
Is like trying to study in a mirror, reflection,
Searching through image after image,
Suddenly scared that I won't find perfection.

But everything has changed so completely,
A Mrs not a Miss, the gold band i now wear,
An us not a ME, A wife I've become,
So why should I feel such despair?

Irrational feelings, hopes and fears,
I need to banish them far away,
To concentrate on the new not the old,
And start to live a new day.

For radiant and beautiful I was,
No matter what anyone says, it's true,
My eyes are only for him,
And my love and happiness shines through.

So when I am down and these thoughts return,
My irrational feelings of despair,
I hold on to that perfectly wonderful day,
And it makes it all easier to bear.