I'm sorry you are struggling with this. Since you posted this thread in the Schizophrenia and Psychosis forum, I presume Schizophrenia is something you've been diagnosed with? And, assuming that is the case, my thinking would be that the feelings you're experiencing regarding demons possessing you is related to your illness & is perhaps best treated via psych med's & perhaps mental health therapy.

One additional thought I will offer you though is that the 11th century Tibetan Buddhist yogini Machig Labdrön said: "In other traditions demons are expelled externally. But in my tradition demons are accepted with compassion." Perhaps one thing you might try, if you can, is to learn to simply allow your demons to be there (since they already are anyway) & to recognize that any thoughts they try to impose upon you about hurting others are things you can simply allow to arise & fade as they will without your having to act on them. This is a practice that is referred to as "compassionate abiding". Here's a link to a description of the practice:

Relieve Distress By Allowing It: Compassionate Abiding 101 | Mindset: Perspective Is Everything

May it be of benefit.