There are two kinds of poetry, free form and everything else. Everything else includes all the stuff you learn about in school with the rhyming and couplets and syllable counts and all that. With that type of poetry there is a right and wrong based upon the format. With free form, well, it's free form. There is no format, no right and wrong.

As for the content or message, poetry is all about the author. If you like it, if it means something to you, helps you cope with something, or just gets some feelings out... then it is good poetry. If someone else connects with the emotion of your poetry and gets something from it, than it is very good poetry. If lots of people can relate, then either you wrote a greeting card, #1 smash pop song, and/or great poetry.

So since you decided to share this one, it obviously falls into the category of "good poetry", since it does something for you. I like it too, a bit sad, but then a lot of poetry is.