Thanks a lot for the feedback guys. I've changed it a little to include your suggestions:
Together:
君が 大好き。
かわいくて やさしくて
楽しくて すばらしくて。
それから 君だけと
いつも 一緒にいたい。
愛してるよ。
Separately:
きみがかわいくてたのしくてそれからいつも愛してるよ 。
大好き。やさしくてすばらしくて。君だけと一緒にいた い。
I added a くてto the last adjective in the list to imply there are more in this list, is this ok grammatically? Also how wrong is 一緒にほしい? Unintelligible? Because it rhymed a bit better.
Luckily I think I can write off the lack of punctuation as poetic licence.
Btw Do you think its ok to use 楽しい in this context? I couldn't really think of any other good i adjectives ...