How can one stop repeated adultery while feeling guilty and despairing of God accepting repentance?

Persisting in major sins exposes one to God's wrath, and sincere repentance is accepted, and God forgives all sins. Among the things that aid in repentance is knowing the punishment for the sin. God has promised adulterers a doubled torment on the Day of Judgment and eternal humiliation therein. Also, leaving bad environments, increasing supplications, and remembering God's anger and punishment, death, the Day of Resurrection, and Hellfire are helpful.