Works burned? Accursed?

Can you help me understand James 2:14-26? Our works might be burned up at the final judgment (1 Corinthians 3)? If we don’t love Jesus enough, we might be accursed (1 Corinthians 16:22)? Am I really saved even though I doubt so much?

“Christian, your heart is new, not wicked!”

What exactly is our new heart? Where is it located? What purpose does it serve? Can you expound upon the deep meaning of Galatians 2:20? How should we navigate tough decisions like what movies to watch?