Ainitze Labaka That is great. Repeated exposure to stress or chronic stress among nurses is a very relevant research interest. I wish to hear from your updates soon, please. :-)
Please read Theoretical Foundations in Nursing and Theory Development in Nursing ebooks. But first, who is your favorite theorist? With that, read the theory and then analyze if the theory is still applicable today. And then try to redesign it based on your analysis. While reading the suggested books, it will be so easy for you to understand how to construct your own theory based on your favorite theorist or the theorist that you idolize.