My Father Is 70 Years Old And Just Had Back

My father is 70 years old and just had back surgery. He was doing well after surgery which was 2 weeks. But I have been told that he is having some memory issues and seems to be confused about what day it is. He never had this problem before the surgery. He is on high blood pressure medication and cholesterol medication. He is a diabetic and takes a pill for that. I am not sure what pain medication he is on. I live in Florida and he lives in Michigan so I just can't get in my car to go check on him. Also, he is getting angry and kinda upset with everyone around him.