11. "What troubles me is that I am not sure I have accepted Christ.”

To accept Christ is to receive Him by faith as your Lord and Saviour. But, strictly speaking, the great thing to see is that God has accepted Christ. He took our sins upon Him, died to make propitiation for them. But God has raised him from the dead and taken Him up to glory.
He has accepted Him in token of His perfect satisfaction in His work. Believing this, the soul enters into peace. I simply rest in God's thoughts about His Son.
“Peace with God is Christ in glory,
God is light and God is love;
Jesus died to tell the story,
Foes to bring to God above.”