Was forced out of PhD for academic/health reasons, need advice on what to do next
If you want to continue at the same school I'd start by going to talk to the administrators in your department, hopefully as a PhD student they will be familiar with you and your situation. Ask about your options to continue your studies, and possibly seek out a new supervisor.

I'd also make a list of other schools you'd be interested in attending, and find faculty there with similar research interests, ideally you could try setting up a meeting to discuss your shared interests and ask them if they might be willing to supervise you or if they have any projects that might be a good fit for you as a PhD student.