What is the way to get rid of extreme attachment to a married neighbor's daughter and to overcome lust towards her, and is it permissible to speak with other girls with the intention of marriage in order to distract oneself from this girl?

The matter of zina (unlawful sexual intercourse) is grave, and for this reason, Islamic law has forbidden all paths leading to it. It has forbidden looking, private seclusion (khalwa), and touching. As the Prophet (peace be upon him) said: "The son of Adam has his share of zina decreed for him, and he will inevitably attain it. The zina of the eyes is looking, the zina of the tongue is speaking, the soul wishes and desires, and the private parts either confirm that or deny it." And Allah (the Most High) says: "And do not approach zina (unlawful sexual intercourse). Indeed, it is ever an immorality and is evil as a way." (17:32) And He says: "Tell the believing men to reduce [some] of their vision and guard their private parts." (24:30) And the Prophet (peace be upon him) said: "For a man to be stabbed in the head with an iron needle is better for him than that he should touch a woman who is not lawful for him."

The solution to this is repentance and staying away from this woman. We advise you with matters that will help you rid yourself of this girl, which are: seeking refuge with Allah (the Most High) through sincere supplication that He removes her love from your heart, continuously being mindful of Allah (the Most High) and feeling that He is aware of you, striving against your self to abandon the causes of this, and associating with people of goodness and righteousness. As for talking to other girls, it is a flimsy excuse and a great sin that you would add to your sins.