I bought through the health connector when I was between jobs - but this was many years ago. I believe they have a phone service - have you called them to follow up?
I haven't done this but I believe there are health insurance brokers that you can work with and/or you could join a professional organization that helped facilitate the purchase of health insurance.
One I found - just by Googling (so I make no assurances if they are reputable or not!) is this organization:
https://nasro-co-op.com/self-employed-health-insurance/ma/But I am sure you could find similar organizations.