OK, you said you wanted constructive comments, so I'm planning on picking apart this poem. You can take what you think is valid, and leave the rest. Here goes:

"Tearful raindrops running down my cheek"

"Tearful raindrops" doesn't really make sense. Either the raindrops are crying, or they are just palin tears, and therefore not raindrops, or they are just raindrops, and therefore not tears. It's a fine sentiment you have, comparing tears to rain. Everyone does it, but it's not wrong in itself. You could perhaps say "tears, like raindrops..." It wouldn't make it very original, but it would make sense.

"Childhood memories are easier to meet"

I rather like this line. It evokes some interesting ideas, but they aren't really developed. They're easier to meet than what? Than raindrops? Than the broken heart you talk about later? Tie this in somehow, it has promise.

"My reality's fading slowly down the drain"

When I think of something going down the drain, I can't say I think of "fading." You could have something like a fading... stain, maybe. Something to do with plain... However, if you want to keep the drain part, and maybe change the tone, you could say something like "wheeling down the drain," or "cascading," "whirling," "tumbling," etc.

I don't understand why a broken heart
can cause so much pain.

Why wouldn't it? It's broken, broken things hurt. I understand what you mean - how even though you know it's bound to hurt, you still don't expect it. But you could state that differently.

"I've loved you for so long
I cared so much
but you didn't even realize i was living"

Capitalize "I"

Also... perhaps you could "show" how you cared, rather than just stating it. Do you know what I mean?

"our lifeless friendship has lasted to be so strong"

I was quite confused by this line. How can it be strong and lifeless at the same time? Or, you were strongly bound to him, but there was really no basis... or... yes. "Lifeless friendship" is a pretty interesting concept, to me, because its so opposite from what friendship should be. So, keep that phrase, but make the whole line more understandable.

"My Tearful raindrops would slowly pass"

Pass where?

"The life I am living would go by so fast"

If what? This sound like an incomplete statement. "it would, if..."

"So next time I'm crying theres no need for worry"

there's, with an apostrophe

"its just those clumsy little tearful raindrops"

it's, with an apostrophe. I like that the tearful raindrops are clumsy. I just don't like that they're tearful raindrops, because I still don't know what that means.

Ok, done. I hope I didn't dash your poetic inclinations or anything. Compared to so many poets on here..well. If they got higher scores than 1-2, then you should have, too. I don't think this poem is terrible or anything. And you by no means need to take all of my advice, these were just some of my ideas and reactions. No matter what anyone says, though... keep writing! Good luck, and I hope some of this helped.