What is the ruling on intense fear of God's punishment and the failure to complete a marriage after repenting from masturbation and watching pornography?

One must sincerely repent of bad habits and forbidden acts by abandoning them, regretting them, and resolving never to return to them. If the repentance is sincere, it will be accepted, and Allah will conceal the one who repents. There is no fear that sins will affect one's success, for repentance erases what came before it, and the one who repents is like one who has no sin.