Study your school, department or university's citation guidelines. There are many different citation styles, each with its own rules for citing references. One of the most commonly used is the style guide published by the American Psychological Association.
Consider alternatives to citing yourself in your essay. Could the point you are trying to make be supported in any other way?
Decide whether the reference you intend to use requires a citation. If you are citing a piece of information given to you by someone else, such as a statement during an interview or in a letter, you can cite this as "personal communication." If you are describing your own experience, you should do so without a citation, although you should consider not doing so if at all possible.
Describe your experience in detail if it is absolutely necessary. If describing personal research, such as an experiment or archaeological excavation, describe it in neutral terms with a minimum of editorializing. Avoid discussing yourself and focus on what you observed.