بسم الله الرحمن الرحيم
(Fatwa: 303/300/B=04/1436)
Yes, you may sell your gold, and after deducting the amount of debt whatsoever amount remains in your hand you will have to pay its fortieth part as zakah. Your husband should not have taken the educational loan, as while paying the loan one has to pay the interest and paying interest is haram just as taking interest is haram. You may borrow money from your father-in-law. Whatsoever amount you take from him if you pay it back without any addition then it is lawful without doubt.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband