Ask HN: Advice for a Solopreneur

I'm a solopreneur. This is a throwaway account for obvious reasons.

I'm looking for advice from fellow entrepreneurs.

My online business has done a net of $1M this year. Taking the leap of faith to move from an employee to a business owner has been the hardest thing I have ever done. Harder than raising babies. I'm in my 40's and have a family with 4 kids to support.

With an online business my expenses are a very small percentage on my revenues. What options are available to legally reduce my tax bill? Another way to look at this is to focus on income generation and not worry about the tax bill.

Here is some more personal context with my situation:

Private high school cost for 4 kids will be: $245k

Solo 401k contributions are maxed: $57k

529 contributions are maxed: $16k

Living expenses for 2020: $50k

=== So if my taxes for Fed, State and Local come in around 40% ($400k), that leaves $600k.

$600k less the above is $222k.

I'd like to lower my tax bill so our next house will not have a mortgage.