Losing employer insurance, where should I look? (update)

My employer coverage ended at the end of the month and I am trying to work out what to do as a teaching assistant. The COBRA notice arrived with a very high price. How fast did coverage start?

Losing job-based coverage usually opens a special enrolment window, so check the deadline on the official marketplace site. I missed it by a day once and regretted it.

A free navigator at a community health centre walked me through my options. It took an hour and saved me a lot of guessing.