The feeling that something or someone else is controlling your thoughts or actions is actually a symptom of psychosis.

I am religious in my own ways, I'm not Christian but I believe in angels and demons, etc.

But, as a priest I saw once said, an actual posession is something that is extremely rare. Many, many are reported. But, actual real ones are so rare that if you see one in your lifetime, that is considered a lot.

And, many places who perform exorcisms do way more harm than good. There are reputable people who practice them, but there are also many people who can damage your psyche and well being. It's something to be aware of.

As for science and doctors being able to figure the cause of all this or how to fix it, really doctors and science are not as far advanced as some of them want to think they are. Sure, we know a lot, but some things are still farther along than our capabilities at this time. The brain is a very complex thing and science is relatively new by comparison. Perhaps if the Roman's had not been overthrown and the library in Constantinople had not been burned, then we would be much farther advanced now than we are. Unfortunately, science was derailed at many points in history for various reasons.

Another consideration is that science gets held back by political agenda, corporate agenda, greed for profit, etc. We could very easily have homes powered by alternative energies other than fossil fuels. But, solar power is free versus millions of dollars for oil. There types of medicines that are widely used in Europe, for example, which are effective for many illnesses, but they are not used in the US? Why? Because of corporate positioning. It has nothing to do with the health and well being of people.

Also, our society itself does not promote mental health, or health at all. We are bombarded wtih messages to be healthy and yet the very core of how we live exhausts us into unhealthy lifestyles.

So no, I don't think it is possession. And, your mom may be just wishing for when you were a little girl but not fully seeing the progression of your illness.