Husband Defaming Wife infront of relatives, school and court

Hi everyone I have been in a contested divorce battle with my husband who filed a false case of cruelty against me and abandoned me 3 years back. I got an interim order from the court which gave him some visitation and he has to pay child maintenance to me. However he is not following the orderWhile I have agreed to divorce him in Jan 2022 (as the marriage became pointless), now he is refusing to give me divorce unless I give him access which is 3x the interim order and take maintenance which is half of interim maintenance order. Therefore our case is not getting resolvedHe has also been badmouthing me to my relatives using Facebook and WhatsApp, telling them that I have separated him from his daughter. He is also going to her school to badmouth me. Can I file a defamation suit against him? nnAbove all what can I do to expedite the divorce, since we have been separated for about 3+ years and he had filed the divorce himself.