All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
Your husband does not have to obey his father in divorcing you without an acceptable reason, because obedience is required only in what is permissible. However, he must continue to treat him kindly and endeavor to convince him to change his mind concerning this issue. If the father insisted on his stand, then your husband is not blamed if he disobeyed him in this matter, because this is not considered undutifulness to parents. In such a case, the threat of his father is harmless as long as your husband performs his duties towards him properly. For more benefit, refer to Fatwa 84056.
However, you should supplicate Allaah The Almighty earnestly and He will be sufficient for you in everything, as He said (what means): {And whoever relies upon Allaah - then He is sufficient for him.}[Quran 65:3]
Moreover, be sure that Allaah The Almighty will never forsake you as long as you are satisfied with His Decree and obedient to Him. Allaah The Almighty said (what means): {…he who fears Allaah and is patient, then indeed, Allaah does not allow to be lost the reward of those who do good.}[Quran 12:90]
Allaah Knows best.