It's important to remember that I cannot provide a definitive diagnosis.
Hearing someone laughing at everything you do and feeling like you are being watched or monitored is an experience that could be distressing and cause concern. However, it does not necessarily mean you are experiencing psychosis.
Psychosis is a mental health condition characterized by a disconnection from reality. Common symptoms include hallucinations (seeing or hearing things that others do not), delusions (false beliefs that are firmly held despite evidence to the contrary), disorganized thinking, and other cognitive impairments.
The situation you described might be related to social anxiety or feelings of being monitored or judged by others, which can be distressing but not necessarily indicative of psychosis.
To understand what you're experiencing better and determine if there's an underlying mental health concern, it's essential to consult with a qualified mental health professional. They can conduct a proper evaluation and provide appropriate guidance and support based on your specific situation.
If you find the behavior of your neighbor troubling or intrusive, you might also consider discussing the matter with them calmly and directly or seeking advice from local authorities or community mediation services if needed. Open communication and conflict resolution can sometimes help address concerns between neighbors.