Hi there!
Writing a thesis or dissertation is really challenging, especially if you don't have much guidance from your supervisor. I would know, as I just submitted my Phd thesis and had very little input from my supervisor throughout the processs.
The discussion is probably the most significant chapter, because this is when you discuss your findings in view of what's already established in the literature and make connections to broader issues relevant to your area of study.
My thesis is in Discourse Studies (doctor-patient talk in making decisions about insulin), but as an academic editor, I've assisted with theses, articles and academic documents in various fields. I also read many dissertations from top universities while completing my thesis. There are definitely many aspects of good thesis writing and academic discussion which are common across all fields. And incorporating these will help you build a substantive discussion.
For this task, I would first read the existing thesis chapters, and any other theses or articles that you feel are most relevant. This will help me understand your field, research aims and purpose, and your data/findings. Any comments from your supervisor would also help. Then, if you haven't started writing your discussion chapter, I would prepare a recommended chapter outline, with headings/sub-headings etc. and a rough description of what should go into each section.
Feel free to get in touch if you'd like to discuss this further.
Ayeshah