Why are adult children of deceased husband harrassing me about what they think their father may have had?

husband deceased, didnt have a will, no need for one, why are his adult children, i am not their mom, getting small claim affadavits trying to collect on insurance policies and health policies that clearly belonged to me and my husband? they moved his body which was at hospital morgue, awaiting my signature, a long lost son, who i didnt even know, had it taken to some funeral home, and then the funeral home had enough nerve to think i was suppose to pay him for services that he performed, my husband rquested to be cremated. Are there any suggestions on what to do about these people and how they are carrying on, i had medical power of attorney, but they are being downright disrespectful, had his mailing address changed with no authority, post office mgr stated they showed up with papers stating that the son was executor of his estate, how is that, and i was never contacted by any legal authority, the mail change was done second day after my husband died, what judge in america appoints an executor without contacting a spouse FIRST?