I don’t believe God will forgive me for what I’ve done

There is no one who is not within God’s ability to save.

(Rom 10:13 NIV)  for, “Everyone who calls on the name of the Lord will be saved.”

In fact, Jesus came to earth to call sinners to repentance. His message is not for people who think they are good enough for God.

(Luke 5:31-32 NIV)  Jesus answered them, “It is not the healthy who need a doctor, but the sick. {32} I have not come to call the righteous, but sinners to repentance.”