I will not reach forever

Quick start, quick end: how do I show you I love you in so little time?

Unconventional meetings
On which we took a chance
Now we're meeting
Every night just to dance
Around each other's heads
And share every thought
But what if it were then
That I shut one part off?
What if I didn't tell you
I never planned to meet
Someone so beautiful,
So perfect for me
Because I don't have long
And I don't know exactly when
But pretty soon I'll be gone
I don't want to scare you
Even though I feel I should just leave
Instead of letting you be the one
To find me in the past, on the floor
Would it be better if you knew?
If I kept my heart in my sleeve?
I'm not leaving on purpose
I have no choice in this
This heart of mine is weak
And it would be so quick
They don't give me good odds
For seeing your next birthday
My reality is so flawed
I've got the perfect present in mind
And a proposal to awe the world
But if I don't make it till then
How do you want to be told
That I wanted to spend forever with you
But my body wouldn't let me
You're so beautiful
I'm being so selfish
This puzzle leaves my mind reeling
But I don't want to let you go
Until this heart stops beating

Author's Note

I fully appreciate reviews, especially when they tear apart my work in an attempt to make it better. Rip, tea, break it down. Tell me how you do not like it, how to make it better. I want your opinion. Truly.