I understand your situation now. It is unclear whether you have already aborted. Your father in law might be suffering from few psychotic symptoms from whatever you have mentioned. However more clarity is needed regarding his habits like alcohol use, sleep and hunger, concentration at work etc. as well. He would require a detailed evaluation by a psychiatrist. After confirming the diagnosis it is easily manageable with appropriate treatment. Some counselling sessions along with medical help also might be useful for him. I would also be more than happy to help you with that if you are looking for further online assistance. Discussions will be held confidential. You can directly consult with me through Practo as needed. Online chat consultation is also available.