What should I do about my feelings of guilt towards a girl I wronged in the West, knowing that my family wants me to marry another woman to obtain residency, and I have prayed Istikhara but nothing has become clear to me?

The relationship with the girl must be severed, and one must repent to Allah by abandoning the sin, regretting it, and resolving not to return to it. It is recommended to proactively seek marriage with a religious woman. Obeying one's parents takes precedence over marrying a specific girl, and there is no sin in not marrying her. It is also important to note that residing in non-Muslim countries is not permissible except under specific conditions.