words fail me

I cannot find the proper words to describe my thoughts and feelings; I am unable to express my reaction, often because the situation is shocking, surprising, or unusual; we can also say "I'm speechless."

     1. Words fail me when I think of what he has done!
     2. I would like to tell you about the difficulties in this African country but I can't. Words just fail me!
     3. Words fail me to describe how beautiful was my girlfriend in her new dress.

P.S.