"And oh, it's at the tip of my tongue,
but I just can't seem to say the words to you."
-Ohhh, Jen. This is exactly how I'm feeling right now also! I want to tell him those words, but they just won't come out. :] I already can tell.. I can relate XD

"Couldn't help to think of all the fun
we have even during "horrible" weather."
-Okay. I came over something minor here. "Couldn't help [but?] to think of all the fun ..."
The but really isn't needed, but to me.. it sounded better. You choose what fits best. :]

"You are my dandelion clock
and my unwrapped Hershey's Kiss.
Like the birds in a perfect flock,
you're everything I miss."
-This is cute! Haha. I love how you worded this. It's great. :]

Overall, I love how you repeated your first stanza as your last. :] Wow. I really enjoyed this poem.. I felt as though I could relate to this one! 5/5