You can retire now, and I think you should.
Regarding health insurance: Research info about the ACA. Healthsherpa.com has a lot of information. You can also go to healthcare.gov or your state’s exchange and browse health plans to see what is available for you and to see if your doctor’s and hospital systems take the insurance plans. Most do.
Part of the ACA is that pre-existing conditions are now irrelevant, except for short term plans that are not through the ACA. Insurance on the ACA is substantially like insurance through work. To qualify for a (substantial) subsidy, you need to keep your MAGI under about $69K for two people, for the years 2023-2025, then you will be enrolled in Medicare and the ACA becomes irrelevant. To qualify for cost sharing reductions, your MAGI needs to be below about $41K for two people. This is important if you have or anticipate substantial out of pocket expenses, which you should. You also need to keep your MAGI high enough to avoid Medicaid.
Your asset situation makes all this easy for you to do. You have rental income. You have a large 401K, from which you can draw a small amount each year to keep you away from Medicaid. Then, you can live off of your cash for the rest of it. Delay SS until full retirement age.
Last, get out of 100% equities in your 401K. It’s been a nice ride but that is probably ending.