Question: I have repented of my divorce, so why can't I remarry?
Answer: Did you repent of your divorce or actually attempt to repent of your marriage? Most people say that they repented of their divorce, but the very fact that they want to remarry proves they did not repent. Claiming to repent of divorce and yet wanting to then remarry would be like the thief "repenting" of stealing money and then planning what he is going to buy with the money. True repentance would not try to profit from the sin being repented of. True repentance shows forth fruit worthy of repentance. You will restore what you stole and make things right. You will not, as much as possible, profit from your sin that you are repenting of. If you repented of divorce then your only option would be to be reconciled to your spouse or remain without remarrying. Here are some Scriptures that might help you better understand what works true repentance brings forth.
Acts 26:20
20 But shewed first unto them of Damascus, and at Jerusalem, and throughout all the coasts of Judaea, and then to the Gentiles, that they should repent and turn to God, and do works meet for repentance.
2 Corinthians 7:10
10 For godly sorrow worketh repentance to salvation not to be repented of: but the sorrow of the world worketh death.
Hebrews 6:1
1 Therefore leaving the principles of the doctrine of Christ, let us go on unto perfection; not laying again the foundation of repentance from dead works, and of faith toward God,
Proverbs 28:13
13 He that covereth his sins shall not prosper: but whoso confesseth and forsaketh them shall have mercy.
The story of Zacchaeus is also another good example of a truly repentant person (Luke 19:1-10 below).
Luke 19:1-10
1 And Jesus entered and passed through Jericho.
2 And, behold, there was a man named Zacchaeus, which was the chief among the publicans, and he was rich.
3 And he sought to see Jesus who he was; and could not for the press, because he was little of stature.
4 And he ran before, and climbed up into a sycomore tree to see him: for he was to pass that way.
5 And when Jesus came to the place, he looked up, and saw him, and said unto him, Zacchaeus, make haste, and come down; for to day I must abide at thy house.
6 And he made haste, and came down, and received him joyfully.
7 And when they saw it, they all murmured, saying, That he was gone to be guest with a man that is a sinner.
8 And Zacchaeus stood, and said unto the Lord; Behold, Lord, the half of my goods I give to the poor; and if I have taken any thing from any man by false accusation, I restore him fourfold.
9 And Jesus said unto him, This day is salvation come to this house, forsomuch as he also is a son of Abraham.
10 For the Son of man is come to seek and to save that which was lost.