although i probably have no chance to go after you, but still would like to tell you that you're an unique girl who made my heart be melted この表現は自然ですか？

"Although I may have no business going after someone like you, I cannot hold in these surging emotions inside of me any longer - you're the one and only girl who made my withering heart melt"
If you were to go full poetic it'd sound something like this.
If I was to just fix up the original sentence( assuming the context to be 2 high school something or something along those lines):
"Although I may be out of your league with no real chance at making this work, I'd still like you to know that you were the one who melted my heart"