is this a good poem?

Well, as a poem it actually has little to recommend it, but...

It may all be true, and it may describe your feelings well, but poetic language should elevate a thought or description above that of an everyday paragraph.

If you insist on plain description, perhaps you should use some poetic structure such as meter and rhyme, or blank verse, which is unrhymed iambic pentameter. Your words can be plain, and your structure sentences, but you could make them march and, perhaps, sound poetic.

Also, rewriting is part of poetry. You have a list of ideas you wish to express here. Now go and find a poetic expression for each idea.

Added edit: Well, it's not a bad start, but even Lucy Van Pelt told Charlie Brown that a true work of art takes at least an hour!

I think it is a good as you can expect from a poem that took you 15 minutes. What makes something a poem and not a piece of prose divided into short lines and verses is a debate that has gone on for centuries and will probably never fully be resolved. For me this reads like prose. Also the language seems a little strained in places for example "you have taught me much in these harsh times" it seems as though you are trying to make it sound poemy. Seriously, would you say that? I doubt it. And "this day can not be very few" What???? You have something you want to say but I think you are trying too hard. Poems don't need to be long or use clever words. If you have to twist the language to make it fit is can be annoying and distracting for your reader. Say it from your heart, make ever word count. The poem will work much better.

I think it's a good poem, but I don't understand who the "leader" is meant to be? Are you referring to one person in particular, like the president? Or is this person a family member like your parents or a sibling? If the leader is a friend, I would change the part where it says "Since I have been born till this very day, You have never let me down"... because obviously it takes time to get to know a friend well.

I think it requires much work. It doesn't allow too much imagination to the readers as only conclusion, not description is seen. Better work on it and spend much more than 15 minutes on your poem.

How old are you? Did you write it yourself? Is it for a class or just for fun?

Edit - I wanted to wait and see how old you were because that affects how harshly I will critique your poem. However, I think Longshiren made all the points that need to be made, so just go with what he said. :)

Somewhat wordy but it is very good.