I have so many things that
I have so many things to do.
Tengo tantas cosas que quiero decirte.
I have so many things I want to tell you.
Tengo tantas cosas que decirte que no sé por dónde empezar.
I have so many things to tell you that I don’t know where to start.
Tengo tantas cosas que no necesito.
I have so many things I don't need.