Q: What is the misery of that estate whereinto man fell?
A: All mankind by their fall lost communion with God, are under his wrath and curse, and so made liable to all miseries in this life, to death itself, and to the pains of hell for ever.

Genesis 3:8, 24. And they heard the voice of the Lord God walking in the garden in the cool of the day: and Adam and his wife hid themselves from the presence of the Lord God amongst the trees of the garden... So he drove out the man; and he placed at the east of the garden of Eden Cherubims, and a flaming sword which turned every way, to keep the way of the tree of life.
Ephesians 2:3. Among whom also we all had our conversation in times past in the lusts of our flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath, even as others.
Romans 5:14. Nevertheless death reigned from Adam to Moses, even over them that had not sinned after the similitude of Adam's transgression, who is the figure of him that was to come.
Romans 6:23. For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.

Westminster Project - See Matthew Henry's Scripture Catechism based on the WSC for more detail