How to explain a three year employment gap due to being ill? [on hold]

For the last three years I have been ill, and need to focus intensively on treatment. I've finally reached the point of my health being stable.

I'm new to UX design. I have started case studies on my own, and received very good feedback. Several employees from the company I did one on reached out to me and commended my work, for example. The company is large and well-known. I'm pretty confident that if I applied to a job there, I have a chance based on skill alone.

The problem is 1) I haven't worked for three years due to medical treatment, and 2) I have not finished my degree, though I did attend a top-ranked university. For money reasons, I won't be returning to for at least the new couple of years.

I can show the skill, but I don't know how to spin my long very long employment gap and lack of employment in general. Do I explain or disclose that I was sick, for example? Since employers normally see the resume first, I'm not sure how to write mine due to lack of experience as explained above. In other words, I'm totally lost and could use some insight from others in the field.