Health insurance before Medicare is definitely possible. The ACA ( Obamacare ) provides subsidies to those with low or medium income. That means if you spend from cash savings, healthcare can be affordable. ( But note that in doing so you are going to pay more taxes in the future, because you are foregoing Roth conversions, which show up as income and reduce the subsidies. )

Early retirement is absolutely attainable. To hear stories ( of questionable provenance), visit FIRE forums. I can personally attest to knowing people that have done it— married people with kids. It takes nowhere near the figure you’ve cited. Listen to retirement podcasts, you will hear from plenty of people that have done it.

To get real, actionable advice join the Bogleheads community. Good luck.