All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
First of all, may Allaah reward you, dear sister, for wishing goodness for yourself and for willing to preserve your dignity and fearing affliction. We ask Allah to make you firm and steadfast on His Religion until you die.
As regards your question, you are not Islamically obliged to work until you repay your father's debt especially that you were not the cause of this debt. Moreover, the fact that the men with whom you work keep bothering you at work and that no matter how serious you try to be, you might fall into doing something against the Sharee’ah, like shaking hands with men, then this is enough a sound reason to give up this job. It is even an obligation on you to leave this job in this case even if this leads to your father being angry with you, as Allah ordained you to obey your father in what is not a disobedience to Him [to Allah]. Mixing with men in this way is a great sin and there is no obedience to a creature in disobeying the Creator.
Finally, you and your father should know that Allah Says (what means): {And whoever fears Allah — He will make for him of his matter ease.} [Quran 65:3]
Allah knows best.