What is the ruling on suppressing one's desire and delaying ejaculation while caressing or embracing a non-mahram woman, and what is the expiation for that? And what is the way to stop masturbation and control one's desires?

Masturbation is forbidden and has many harmful effects on a Muslim's religion and body. If someone advises you to masturbate, they have deceived you. You must avoid things that provoke lust. If lust arises, occupy yourself with acts of obedience, remembrance of Allah, and the company of righteous people. Avoid solitude and bad company. And supplicate with this prayer: "O Allah, I ask You for guidance, piety, chastity, and self-sufficiency." What you mentioned about whispers is from Satan, who gains power over those who commit sins, so seek refuge in Allah from him. Masturbation is not permissible, and you must repent to Allah Almighty for what you have done. Madhī (pre-seminal fluid) is impure and necessitates wuḍūʾ (ablution), not ghusl (definition) (ritual bath).