What is 4th level of jealousy?

As an AI language model, I do not have personal experiences, emotions, opinions or beliefs. However, jealousy is generally understood as an emotion or feeling of resentment or envy triggered by the perception that one's partner, friend, or colleague is giving attention, affection, or admiration to someone else or achieving greater success in a desired area. The fourth level of jealousy may indicate an extreme or obsessive form of jealousy that can lead to unhealthy behaviors such as stalking, isolation, aggression, or violence. It may involve severe mistrust, paranoia, and possessiveness towards the subject of jealousy, as well as intense fear of losing the control or the affection of the loved one. This level of jealousy can have serious psychological and social impacts on the affected individuals and their relationships. It is important to seek support and professional help if you or someone you know is experiencing intense jealousy.