COBRA quote is huge, any alternatives? after 11 years as a bookkeeper

The COBRA quote for my family is $500 a month and I do not know how to afford it. I have read a lot of threads here and could not find my exact situation. My old employer will not help with the premium. How did you decide?

I priced both side by side: total yearly cost, doctors in network and the deductible. Marketplace was cheaper for us, but only because our doctors were covered.