Some choices are undo-able, but remember God is ready to forgive and give you a second chance. 'If we confess our sins, He is faithful and just to forgive us our sins and cleanse us from all unrighteousness' 1 John 1:9.
God is a God of miracles and He can make you feel clean once again. When you confess and forsake your sin, God will forgive you. Please learn to forgive yourself and move on.
When David committed adultery he made a big mistake. But God made good of it because Solomon was born out of that marriage and he was one of the greatest kings of Israel. Read about it in 2 Samuel 11/12.
Believe God to turn your mistakes into a blessing.