I think something or someone is trying to put thoughts in my head to control me

Delusions

Distressing thoughts, beliefs or delusions, such as feeling you’re being followed, overheard or that someone is interfering with your thoughts, body or actions. Paranoia is a feeling or sense that someone or something intends to do us harm, when there is no supporting evidence. If you have paranoia, you find it difficult to feel safe, even when shown evidence or given assurances that you’re not in danger.

This level of conviction and inability to change one’s mind is called a delusion; you have an unshakeable belief in something that is untrue. A person with persecutory delusions may believe an individual or organisation is making plans to hurt or kill them. A person with grandiose delusions may believe they have power or authority – you may think you’re the President, or you have the power to bring people back from the dead.

When you have psychosis, you’re often unaware that your delusions aren’t real, and this can be very scary and upsetting.