Why does Allah not relieve the distress of a woman who feels sadness and psychological weakness, suffers from painful past memories related to her marriage and her failure to form friendships, feels she is being punished for a past sin from which she has repented, and fears that her doubt concerning the afterlife might be disbelief?

If the repentance from disobeying one's mother and masturbation is a sincere repentance, then what is happening is not a punishment for these sins. One who repents sincerely is not punished, neither by religious law nor by divine decree. The tribulation may be due to other sins or for other reasons, and a person should always renew their repentance. One must beware of Satan's whispers, renew general repentance, rely on Allah, and frequently engage in remembrance of Allah and supplication.