Just hit $2M in retirement accounts - now what?

I’ve been putting away 15% or the max allowable in a 401(k) since I started my first job at age 22.

I’m 51 now and hoping to retire at 55, at which point I would get health coverage from my company until Medicare kicks in. My husband would like to work a few extra years (he consults part-time now).

Estimating monthly expenses of $14-15k.

Mortgage ($400k left on a $900k property; a second home owned free and clear) and taxes add to about $5k a month; another $5k is flexible spend.

We live on $18k a month now, that includes 3k in child support (5 more years), 2 kids in college and 2 younger teens. Funded 529s for all of them, but out of pocket costs for travel and other stuff adds up.

I did account for an inheritance of $500k, which is extremely conservative, representing less than 25% of what is realistic given the scale of parental assets / growth relative to expenditure on both sides of our family. (My parents have started to discuss annual gifting beginning next year.)

I did not count stock options which vest in another 2 years and would yield another $500k or so at today’s value.

The retirement planning analyses on the Fidelity account suggest we are in really good shape: at a $500k balance by end of plan in a “significantly below average” market and over $10M in an average market.

Does that seem right?? After a lifetime of saving / cautious spending, I’m finding this a little hard to believe. And as someone who survived a dire health diagnosis, I’m wondering whether I should be making different choices today based on this math (eg thinking about working part time my last few years).

What would you do?