What is the ruling on vowing to fast every Thursday for the sake of a football match, and how can one expiate this vow given the difficulties at work and in studies?

A vow contingent upon an undesirable condition is disliked, but it must be fulfilled if the condition is met. So, if the condition upon which you made your vow is met, you are obliged to fulfill the vow, and it becomes incumbent upon you to fast every Thursday. It is not permissible for you to offer expiation for this vow as long as you are able to fulfill it, due to the Prophet's (peace be upon him) saying: "Whoever vows to obey Allah, let him obey Him." As for one who is unable to fulfill the vow, there are other rulings for them.