I was in the same situation (though a bit later in life than you), and here's my advice.
1) Reduce working hours. Do this immediately. Every day you work 14h+ will extend your burnout by weeks, so stop now. Yes, dropping your working hours may affect your work output, but it's completely worth lower performance at work. A bad performance review is nothing compared to long-term burnout.
2) Take a break. At least a month. More is better. Many startups with successful exits are good about giving sabbaticals to the high performers that got them there.
3) Spend some money on therapy. With that much money, even if therapy does nothing it's still worth it. For me, even the weekly break to go to therapy was useful.
4) You don't have to spend the money on anything right now. I suggest depositing a portion of it into index funds on a monthly basis. You don't need the added stress of figuring out the perfect investment method, and with that amount of money nearly any safe investment will provide a passive income you can live on for forever.
5) I urge you to consider leaving your job. If the politics and coworkers really suck that much, then why do you even want to be there? There's always a few other companies in the same field, and one of them is definitely a better environment. Getting a startup to a successful exit makes you more than qualified to work at one of these other places.
6) Take some time to realize how fortunate you are. Realize how much room for making mistakes you now have. You could take the next 5 years completely off and still be ahead of nearly everyone in the world financially, and career-wise.
I am partway through recovering from the same situation. At the startup, I was a high performer, but occasionally got bad performance reviews due to politics and burnout. Looking back, I should have taken care of myself and aimed for even worse performance reviews. Bad environments don't deserve your stress and hard work.
Eventually I left, took a very long break, and eventually started interviewing again. I'm now at a different company in the exact same field, with better leadership, lower stress, and standard working hours. Ironically, the company has even better productivity than the high stress startup.
1) Reduce working hours. Do this immediately. Every day you work 14h+ will extend your burnout by weeks, so stop now. Yes, dropping your working hours may affect your work output, but it's completely worth lower performance at work. A bad performance review is nothing compared to long-term burnout.
2) Take a break. At least a month. More is better. Many startups with successful exits are good about giving sabbaticals to the high performers that got them there.
3) Spend some money on therapy. With that much money, even if therapy does nothing it's still worth it. For me, even the weekly break to go to therapy was useful.
4) You don't have to spend the money on anything right now. I suggest depositing a portion of it into index funds on a monthly basis. You don't need the added stress of figuring out the perfect investment method, and with that amount of money nearly any safe investment will provide a passive income you can live on for forever.
5) I urge you to consider leaving your job. If the politics and coworkers really suck that much, then why do you even want to be there? There's always a few other companies in the same field, and one of them is definitely a better environment. Getting a startup to a successful exit makes you more than qualified to work at one of these other places.
6) Take some time to realize how fortunate you are. Realize how much room for making mistakes you now have. You could take the next 5 years completely off and still be ahead of nearly everyone in the world financially, and career-wise.
I am partway through recovering from the same situation. At the startup, I was a high performer, but occasionally got bad performance reviews due to politics and burnout. Looking back, I should have taken care of myself and aimed for even worse performance reviews. Bad environments don't deserve your stress and hard work.
Eventually I left, took a very long break, and eventually started interviewing again. I'm now at a different company in the exact same field, with better leadership, lower stress, and standard working hours. Ironically, the company has even better productivity than the high stress startup.