Will God forgive a girl who exploited a young man financially and emotionally, then got engaged to someone else without an apology, and is the young man to blame in this situation?

You are responsible for the pain and psychological distress that occurred due to the forbidden communication and relationship you established.

Imam Ibn al-Qayyim states that the causes of chest tightness are turning away from Allah, attaching oneself to others, being heedless of His remembrance, and loving other than Him. And whoever loves something other than Allah will be tormented by it, and his heart will be imprisoned in that love, so there is no one on earth more miserable than him.

Imam Ibn al-Qayyim's advice: There are two loves: the love of Allah alone, which is the paradise of this world and the joy of the soul. The love of what is other than Him, which is the torment of the spirit, the grief of the soul, and the imprisonment of the heart.

He also says that whoever loves something other than Allah, harm will befall him, whether he attains his beloved or loses him. For if he loses him, he will be tormented by his separation, and if he attains him, the pain he experiences will be many times greater than the pleasure.

You should turn the page on this relationship, repent to Allah, and dedicate yourself to what benefits you in your religion and your worldly life. The Prophet, peace and blessings be upon him, said: "A strong believer is better and more beloved to Allah than a weak believer, and there is good in both. Be keen on what benefits you, seek help from Allah, and do not lose heart. If something befalls you, do not say, 'If only I had done such and such,' but say, 'Allah has decreed, and what He wills, He does.' For 'if only' opens the door to the work of Satan."

This hadith emphasizes the importance of being keen on what benefits and seeking help from Allah. Make your greatest provision for salvation seeking help from Allah, relying on Him, and frequently saying, "There is no might or power except with Allah." Seek a righteous wife and hasten to marry to protect your chastity.