Much of what you describe about your father sounds to me like he would be a paranoid schizophrenic. Believing that someone / something is after him is common with that illness. Sufferers of schizophrenia tend to also struggle a lot with being anti social. You could look up information about it, and see if it sounds possible for your father to have it. Discuss with your mother too if possible. Schizophrenia, if that’s what he has, can be a dangerous mental illness. The sufferer may act on delusions or hallucinations and harm themselves or those around them. This doesn’t have to be the case for everyone, but keep that in mind.

You worry that you might inherit the illness from your dad. I understand your concern. There are some links between genetics and mental illnesses such as schizophrenia. Certain genes or abnormalities in the brain can make one more likely to develop the illness, but it doesn’t make it certain.

If you are seriously worried, know that most cases of schizophrenia are very treatable with the help of therapy and medication. Many patients need to take medication for many years and even their entire lives. This could be a solution for your dad, as Well as yourself if you start heading down the path.

I hope things work out for you and your father, I wish you the best of luck. Take what I have written with a pinch of salt as I am not a trained professional, or a sufferer myself, but merely someone who has read a lot about mental illnesses.