I feel like I can't stop loving this girl.
Why do you feel so in love with this girl?
It's my forever pain. I can't be without her.
Give it some time. I know that it seems like forever, but eventually your feelings will change. You will be able to move on.
You can't say that you understand what I'm going through. Please stop.
I think that everyone has been in love with someone else at one point or another. At first it seems like you are drawn to them only, but in time, you will have other romances and won't be so attached to them as you once were.