Is money earned from working at a gas station that sells tobacco and other products considered unlawful (haram), knowing that the nature of the work involves tasks other than selling? And is it permissible to leave this job for fear of unlawful (haram) money, given existing financial obligations?

It is forbidden for a Muslim to sell tobacco and other prohibited items in Muslim and non-Muslim lands. It is also impermissible to work in an establishment whose primary activity is forbidden. As for entities whose primary activity is permissible but include some forbidden activities, it is permissible to work there, provided that the Muslim does not directly engage in the forbidden act, nor directly assist in it. Regarding the limit of necessity that permits forbidden work, please refer to Fatwa (definition) no. 141838.