1. I miss you so much and I want you here with me.
2. You're always on my mind.
3. I couldn't stop thinking about you.
4. It is painful pining after someone and boy I do pine for you.
渴望、思念一个人是痛苦的事，男孩，我真的很想你。（*pine after/for/over someone or something 渴望……；为……而悲伤）
5. You are all that I think about today and everyday.
6. The world looks bleak without you here by my side.
7. I long to see you, kiss you, and hold you in my arms again.
8. You probably know that I love you but do you know just how much I've missed you?
9. The world hasn't stopped spinning since the day you left. I need you to come back to me and make it alright again.