Twelve Thousand Things I Want To Say

This has promise, that much I have to say. You're sort of teetering on the edge of falling into the cliche. Hopefully I can help you find a sturdier spot.

I'd write them in a long epic,
I'd change "in" to "into"
And sleep with it under my pillow at night
Maybe "each night"?
I'd hold you in my arms, like a true romantic
I like your rhyme here, with "epic" and "romantic". You don't need the comma in this line, though, where you have it. You do need one at the end of the line.
Whispering deadly secrets while I hold you tight
Why are they deadly? That part doesn't really have anything to do with the rest of the poem; you don't make any reference to it anywhere else.
You also need a period at the end of the line.
I'd draw them in the sand,
I think you need to replace 'them' with a concrete noun; "words" or "letters". No comma at the end of the line.
And let you gaze at it from afar
I'd change "it" to "them", especially if you change the "them" in the last line.
I'd tell it to a fire fly, resting in my hand
"It" what? Whatever you're referring to with all these pronouns should be restated more often than you do. You mention at the beginning writing "them" into an epic. You don't mention what "they" and "it" and all these pronouns actually are until a couple lines after this one. That makes it confusing to the reader; you don't want them to have to constantly look back at previous lines to figure out what all these pronouns are referring to. You should use the actual word for at least some of these pronouns.
"Fire fly" should be one word, and you need a comma at the end of the line
Then keep it locked safe, in an air tight jar
I'd change the phrasing if this line so that it's clear you're talking about the firefly here. For all the reader knows, that "it" could be referring to what those other "it's" are referring to. Maybe change it to something like this: "I'd tell it to a firefly, resting in my hand,/and lock it safe in an air-tight jar". However, I think the safest thing would be to change "it" in the line before this one to something else.
There should be a period at the end of the line, or at the very least a comma. "Air tight" should actually be "air-tight".
Because there are at least twelve thousands things I only wish
Take out the "only" in this line, because it makes it too long, and you repeat "only" in the very next line.
To tell you, only you
For this line, and the last one, I'd change the words you use. Add more description of the wishing and the telling, to demonstrate to us what he wants to do, and how he would do it, and steer it clear of the cliche. Make it mysterious and indistinct. Maybe, "Because there are at least twelve thousand things I would/whisper in your mind, breathe into your heart". Remember that images, analogies, metaphors are a poet's seasoning, without which the meat of it would be bland, almost tasteless, and not nearly so interesting. This poem could use a little spicing up.
Comma at the end of this line.
At least twelve thousand chances missed
"Wish" and "missed" don't rhyme. I'm not saying you made the wrong word choice here, but if you have to make a choice between using the right word, and rhyming, you should use the right word and abandon the rhyming altogether. Rhyming is an extremely delicate balance and it's very difficult to get it just right. I think your poem would be better without it.
Twelve thousand times I've wanted to be true
This rhyme here, for instance, between "you" and "true" sounds forced. It feels as though you only have this line in here on purpose to rhyme with "you"; that shouldn't be the way at all. I would get rid of this line and instead expand upon the last one: chances missed to do what? And why? Describe it; make pictures of it with your words.
But only succeeded in my fantasy
Again, forced rhyme. I think this line could go along with the last one. You could instead describe what he imagines in his mind, give us a clearer idea of what exactly it is that he's hoping for. You never state it in so many words, and you don't necessarily have to, but you need for us to be able to tell ourselves what he's hoping, in a more definite way than we can now. For instance, I could only guess right now that he's in love with the object of the poem and imagines being with her. But that's not specific enough, and I'm not positive. Make it clear; make it beyond just being with her; show us what he would do if he could be with her. Moreover, why can't he? So now, tonight, I'll give up the hope
This line sounds cliche. I wouldn't have him say that he'll give up the hope; rather describe his state of hopelessness. It doesn't sound like he really was hopeful in the beginning; it was just wishful thinking.
Which is useless, now I see
This is almost a repetition of the last line. If he's giving it up, that means he believes it's useless. This line could go.
Because twelve thousand secrets are hard to bare
The word you want is "bear". Describe; use metaphors. As hard as what?
But cross my heart, I will not mope
Forced rhyme. Ask yourself if you would have chosen that word if it didn't rhyme with "hope"? Use a less common word. Also, I'd find a more creative expression than "cross my heart"; it's a little too commonly used. Create something that's all your own.
For this poem we'll always share
Again, this gives the impression of forced rhyme.
But could you go into a bit more detail with this? Firstly, if he only wished he could tell her the twelve thousand words, and couldn't, how can he share this poem with her? Or is he saying, this is something he'll always remember her by? That's not quite clear.

I thought there were some good ideas in this, even if the theme's a tad cliche. However, decide if you want to rhyme or not, and stick with it. I advise against rhyming, simply because it's so easy to get caught up in proper rhymes and meter instead of choosing the best words for the poem.

I agree that this needs more punctuation. It helps the ideas flow better and your reader doesn't get distracted by thinking "Hey, shouldn't there be a period there?..." As for stanzas, that could be helpful, but it can get away without them. I'll leave that up to you.

And one more small thing:

I would draw them in the sand,
And let you gaze at it from afar.

That's incredible! I would not have been able to make something like that.
I love the concept and all. It's really very touching and makes you think.

Although I do agree with the lady below me. Breaking it into more stanzas would most likely be your best bet.
And maybe a dedication to whom this is about? Ex boyfriend maybe?

Great work.

Niiiece wooork. I liked the concept, but I think there are a few things that could make this even better.

The entire poem seems to rushed for the idea your portraying, which is love, no?

If you could break it up into stanzas and fix the punctuation it would flow easier. And you used contractions often, which is cool if that's your style, but still try not to overuse them.

Like this is what I mean (just suggestions)

I would write them in a long epic.
And sleep with it under my pillow at night.

I'd hold you in my arms, like a true romantic
Whispering deadly secrets while I hold you tight.

I would draw them in the sand,
And let you gaze at it from afar.

I would tell it to a firefly, resting in my hand.
Then keep it locked safe, in an air tight jar.
Because there are at least twelve thousands things
I only wish to tell you.
Only you.

At least twelve thousand chances missed.
Twelve thousand times I've wanted to be true,
But only succeeded in my fantasy.

So now, tonight,
I'll give up the hope.
Which is useless, now I see.
Because twelve thousand secrets are hard to bare.
But cross my heart, I will not mope.
For this poem we will always share.


--The breaking it up into stanzas really helps the readers eyes follow the poem more, but the contractions thing is just an artistic intuition decision on your part. Haha.

I enjoyed reading this. Keep it up!