Ask HN: U.S. Health insurance during lean, solo, self-funded startup?

Hi YC. I am preparing to leave my cozy big tech job making good money with fantastic benefits to start my own business in my line of work (security consulting). I'm very comfortable with the work itself, the process of attracting clients, the scoping and CYA/legal paperwork and liability insurance, preparing and delivering the reports, forming the legal entity and paying applicable fees to the state government using their website, generally all aspects of the business.

This will be a self-funded business with an extremely long runway (in a good and contractually stable living situation with my childhood/teenage/adult best friend, paying virtually nothing in rent (percentage of net income up to a limit)) - this is a stable situation with extremely synchronized understanding of responsibilities of each party. To be clear, I am living on less than $500/mo, and my investments provide more than this, with rock-solid monthly cash distributions around $1100/mo.

My question is about insurance. Given my operating income of ~$600/mo after expenses (very little taxation at this income level), I am concerned about the cost of health coverage and am wondering if any other founders / small business owners have dealt with similar situations.

I have found healthcare.gov plans with ~$250-$300/mo premiums. I'm young and healthy and have a great doctor who refills my single generic prescription visiting her just once a year. Even w/o insurance, my annual costs are less than the monthly premiums of what healthcare.gov offers. I really just want catastrophic coverage where I pay ideally $XX/mo, have an $XX,XXX annual out of pocket max & deductible, but that doesn't appear to be an option in my state's healthcare.gov program.

Has anyone found a solution for this? Are there umbrella insurance policies that cover some crazy rare medical issues with six digit bills? Am I going to be eligible for Medicaid with considerable assets but extremely little income (until I start having revenue rolling in) in an HCOL area? I know some tax credits are available for the $250-$300/mo healthcare.gov plans for low income folks, but that'll come as a tax credit once a year and thus I'll still be cutting my operating income in half, if I'm even eligible for it (again, six figures worth of assets).

What have fellow HN'ers in similar situations done, and what would HN'ers in such a situation do, barring "stay at the comfy big tech job"?