Your writing this love poem, when it began it seemed like it was a proper love letter to your partner, nothing bad in it. Yet then you suprised me by this stanza;
"I tell you that I love you,
but I haven't heard you say it back."
I found this part suprising as it was unexpected. Then you go on, back to this love poem idea. Apart from the suprise i thought the poem was a little cliche. It seems everyone writes about this kindof love. The flow was ok. Try using varied punctuation including enjambment. It may help it. Other then that a good read. Keep writing! xx