"You shine like the sun
And dazzle my eyes"

^^ I love those lines, the imagery in those two lines as AMAZING, it created such vivid visuals for me.

In fact, I love all of the imagery portrayed throughout this piece, it's beautifully created.

Flow is okay for the most part but there is some places where it's a little of, and I think that's because of the onstant use of fillers (I, and, the etc) Try eliminating some of those and you'll most likely find the flow is so much smoother.

"Even though you do your not a prize"

^^I didn't like that because it doesn't really make sense to me, it seems like you're just trying to match the rhyme scheme, maybe try something else instead?

" I will always show I care
Even if you lose your hair"

^^ Again, I didn't think that made sense and was used just for the rhyme scheme, I thought it came across as somewhat humourous and I don't think that's supposed to be the case as the rest of the piece is filled with so much emotion and depth.

" will never be untrue
Because I love YOU "

^^Favourite lines, easily. So much meaning and depth in so few words and such a strong ending.

The thing I would suggest most is to try and get rid of some of the fillers...maybe try something like:

"Loving you
I will always be true
Knowing you're the one
You shine like the sun
Dazzling my eyes"

" IThere is nothing you don't deserve
I'm holding back with no reserve"

etc etc.

I just think it would even the flow a little.

But other than the fillers, I think this was beautifully written.

Hope I helped some ^^