The $4m in the private tech company - I presume it's illiquid or any chance to sell it?

I'd go back to the seller and offer him 2.75m cash best and final and give him 60 days to consider it. If you really want to shit on his brain put the cash in escrow and have your agent advise him you've done so - as you have the cash sitting already this costs you very little.

In about 45 days things will be far worse in CA and particularly the LA area.

If he comes back you got yourself a reasonable deal, if he doesn't keep your eyes open as it's likely someone over-extended to buy it and it will end up back on the market.

You are in the power seat and do not convince yourself otherwise.