How do you FIRE and support a family?

Reading this sub has been fascinating and also sobering. I am currently on a path to retire at 62, which I used to think was pretty good.

I’m currently 48, about 3.7M net worth (1M house, 2.2M 401K, 300K brokerage, 100k HYSA, and 100K HSA). I live in a very HCOL area. I’ve fully funded my children’s 529s and they should be able to complete a masters program if they want with zero debt. I also made them place all their earning so far into a Roth IRA, but that means I am paying all their expenses. My goal was always to put them in a better starting position than me and maybe they can start building generational wealth.

But that has made it hard essentially supporting a family of fully grown adults. My spouse retired when we had kids and has no intention of going back to work.

Our monthly expenses (including a 3.7k mortgage with about 250k left) are about 10k a month. I’m currently maxing out my 401K and HSA contributions, but my brokerage contributions are a trickle.

From reading the sub, I think I just started too late, but my 30s were family focused and funding 529s instead of my brokerage.

I’m guessing my FIRE number will be about 6-7M, but don’t see RE happening with most of my assets in a 401k.

Anybody have any unsolicited advice? How did others balance family and FIRE on a single salary? I know I’ve already lost my greatest as range of time, but anything else I can do?

I’m about to be an empty nester and it is starting to look painful working another 15 years.