So, I was the wife/homemaker and he did not have a startup. We had an amicable divorce, in part because I wanted to keep lawyers out of it and I have had a college class on Negotiation and Conflict Management. Given that we did not have much money, I did not want the lawyers bleeding us for money we could not remotely afford. So I did a lot of steering that to make it as painless as possible for all parties. He was cooperative, but I at times agreed to things that were a convenience for him because I understood that screwing him over was absolutely not in my best interest.

But if you are negotiating with an idiot who does not understand that bleeding you is a bad negotiating tactic, you need to get better at a) negotiating tactics and b) communicating to them why this is not in THEIR best interest. Don't talk about what you need/want/feel. Talk about how this is likely to impact her, and not in a positive way.

Make absolutely sure you are not making threats. You need to make it clear this will cost her and you need to do so in a way that cannot be construed by the court system as bad faith or threatening behavior and that cannot be construed by her as hot air or empty talk that you won't really follow through on. This is not a scare tactic. The point is to educate this fool.

For example, it might help to get figures on what a nasty, long drawn out divorce litigation costs in both time and money. (I knew we were saving like $40k or more -- money we absolutely did not have -- to divorce without lawyers. That left lots more on the table for us to split, so I didn't quibble about small things.)

Let me also recommend that you pick up "Getting to Yes" and "The Mind and Heart of the Negotiator". They are both research based and were both required texts for my college class on negotiating and conflict management. The first is a quick read. You should be able to get it through in a weekend. The second is much meatier, but I strongly suggest you do your best to find/make time for it as it contains lots of good info.

If you just cannot come up with the money, you may need to do all in your power to insist she accept stocks to cover the part of the business she is "owed."

If you can get a copy of the movie Our House https://en.wikipedia.org/wiki/Our_House_(2006_film) and also Kingdom of Heaven, both contain good lessons in effective hardball negotiating.

Please get your feelings out of the way. You need to be goal-oriented here. This is not about the fact that she is breaking your heart or doesn't love you anymore or a thousand other personal pains involved in the end of most marriages. Keep a journal or do therapy or something, but find a way to get your feelings out of your way when negotiating this settlement.

This is business, not personal. There is enormous money on the table. You must treat it like business -- and never mind that she probably won't. You need to do all you can to avoid getting dragged into her emotional crap or provoking her. Be diplomatic and sensitive to her hurt feelings, but do so in a way that sidesteps the issue as much as possible. Don't pick at old wounds. Don't throw things in her face. Stuff like that will cost you money.

This is advice rooted in having been through a divorce and managing to not screw over either party in the process.

Best of luck.