If you don't pray daily, will you go to Hell?

I heard that all you need to go to Heaven is that you open your heart to God. I believe that Jesus died on the cross for our sins, so that we may become pure and spend eternal life with him in Heaven. I read 11 chapters of the Book of Genesis, but I don't pray daily. Sometimes once a month, I would say this prayer: " Dear Jesus, I know I have sinned against you, and that you have sacrificed yourself, so that we may be pure, and spend eternal life with you in Heaven. Amen." Is that good enough? Do I have to pray daily to be SURE that I go to Heaven? I'm not afraid of death, but I am TERRIFIED at what's will happen to me after death. HELP!