Praise be to Allaah.
Feeling that the situation is dangerous is the most important step towards dealing with it. This feeling is present in your case, praise be to Allaah. Man will always need to strive against himself and give up sin. This is the wisdom of Allaah, so that the sincere and serious believer will be distinguished from others.
Among the most important means of ridding yourself of this problem are:
1. Generating love for Allaah through the prescribed means, such as pondering His Signs and blessings. This will keep you from loving anyone else.
2. Striving to avoid meeting this young man, or sitting with him or looking at him.
3. Stopping yourself from thinking about him, by keeping yourself busy with thoughts of useful things, both spiritual and worldly.
4. If you can marry him - if he is righteous - or someone else, this is the natural solution to many of these problems.
With regard to making du'aa', Allaah answers those who call upon Him and are sincere in their du'aa'. If you say any of the following du'aa's:
Allaahumma tahhir qalbi (O Allaah, purify my heart);
Yaa Muqallib al-quloob, thabbit qalbi 'ala taa'atika (O Controller of the hearts, make my heart steadfast in obedience to You);
Allaahumma iqsim li min khashiyatika ma tahoolu bihi bayni wa bayna ma'siyatika (O Allaah, give me a share of fear of You which will intervene between me and sin);
Allaahumma inni as'aluka al-hudaa wa'l-tuqaa wa'l-'afaaf wa'l-ghinaa (O Allaah, I ask You for guidance, piety, chastity and independence);
Allaahumma Faatir al-samawaati wa'l-ard, 'Aalim al-ghaybi wa'l-shahaadah, laa ilaaha ill anta, Rabba kulli shay'in wa Maleekahu, a'oodhu bika min sharri nafsi wa min sharr il-Shaytaan wa sharakihi, wa an aqtarif 'ala nafsi soo'an aw ajurrahu 'ala muslimin (O Allaah, Creator of the heavens and the earth, Knower of the unseen and the seen, There is no god except You, Lord and Sovereign of all things. I seek refuge with You from the evil of my own self and from the evil and traps of the Shaytaan, and from committing any sin against my own self or bringing evil upon any Muslim)
- all of these are good du'aa's which were narrated from the Prophet (peace and blessings of Allaah be upon him).
(See Tarteeb Ahaadeeth Saheeh al-Jaami': Baab al 'Ad'iyah al-Ma'thoorah).
This must be accompanied by sincerity and persistence in making du'aa'. And Allaah is the Guide to the Straight Path.
