What would you do if you were in my position?

I fail to understand why your father does not want you to study aboard anymore under the assumption that your bisexuality will disappear or that bisexuality is chosen, or that the claim that he is a politician has anything to do with the issue. Is he holding you back from studying abroad until your bisexuality vanishes and you choose to be heterosexual again? If so, nevertheless, if I were in your position, I would pretend to choose to be heterosexual until I am completely independent.