What is the ruling on repeatedly repenting from the same sin, and what is the effect of that on Allah's acceptance of it, and what about the fear of the future?

No matter how great your sin, Allah's forgiveness is greater, and His mercy encompasses all things. So, do not despair of Allah's mercy; rather, trust in His grace. If you sin, hasten to repent. If the sin recurs, do not despair of repenting. Sincere repentance erases the sin and removes its worldly and otherworldly punishment. Thank Allah for His grace, strive in His worship, associate with righteous women, and supplicate to Allah for steadfastness and sincere repentance.