What is the ruling of the Sharia on becoming attached to a girl who does not reciprocate feelings, and what is the solution to this psychological state of pain, loneliness, and heartbreak?

Perhaps Allah intended good for you by your promptness in contacting an Islamic website concerned with fatwa. Allah adorns the love of desires for people, especially women, and the believer knows that this is a trial and a test. Al-Sa'di explained that people are divided into two categories in dealing with these desires: those who make them their objective, distracting them from their true purpose, and those who recognize them as a trial and make them a means to their Hereafter. So, be wary of your devil, your self, and your whims. Know that the fitna (temptation) of women begins with letting the gaze roam, and lowering it is the foundation of preserving one's chastity. Patience in lowering the gaze is easier than patience with the pain that comes after it, for a glance generates desire, then intention, then action. If you desire happiness and tranquility, then you must change what is within yourself so that Allah may change the misery you experience. We advise you to fear Allah and be mindful of Him, to hasten to marry, and to turn to Allah in supplication.