Kate Cassidy,Liam Paynes girlfriend, is mourning the singers death with a touching tribute.

I dont even know where to begin.

You are so incredibly loved.

Liam Payne and Katie Cassidy

Liam Payne and Katie CassidyDaniel Leal / AFP / Getty Images

Im struggling to figure out how to live in a world without you by my side.

Together, we got to be kids again, always finding joy in the smallest things.

You brought so much light into my life.

Justin Bieber and Liam Payne

Liam, I know well be together forever, but not in the way we had planned.

Youll always be with me.

Ive gained a guardian angel, she added.