None of the experts advised you to contact your son. Though you have income, there should be some person to look after your health and other needs. Please search n 'Google" for essentials of claiming adverse possession and where do you stand as per law. The litigation takes a minimum of a decade as adverse possession has to be declared through court.
Life is uncertain. When the law has granted some measures and granted concessions to all senior citizens without legal expenses there should be some attempt to get a legally valid title for further transfer.
When you are in physical possession of the house with all such revenue records in your name, there s no such immediate necessity for you to raise the ssue.
After all your son is your son only, and if at all he wanted to claim a benefit or use the property, like several other unfaithful sons he might have evicted you or sold the property long back as he is having a legally valid title. But he has never attempted such deeds so far and showed his principles and values. The same can not be said of his legal heirs or claimants in the future as they have such right to the property as inheritors.
As of date, there is no litigation issue. You are a senior businessman having exposure to law and you are capable of dealing with the issue on the own with guidance from local advocates.