A very common sentiment expressed -- very -- tritely. Considering that you're working with a sentiment most have experienced to some degree, your primary concern is not in endowing the reader with an understanding of it, but rather in the poeticizing of it. If you want to continue writing poetry, I suggest you experiment with the potential of poetic language: for instance, as an exercise, you might try writing this poem several different ways, each time using different imagery and metaphors. At the same time, however, retain the clearness of expression that you already seem to possess; as it stands, your poetry is more like banal prose. Avoid trite phraseology or word choices like: "once there was a time", "happy", "smile", "cry more than smile", "sorrow I feel is strong", "stranger", "nowhere to belong", "I wish", "sang me that song", "I'm empty", etc. Let your language off its leash! The opposite of banality is novelty, so seek to be novel -- but be sure to still communicate clearly. Then you will make progress.

I agree. Verse 4 has potential - could become the poem.