You're all turned around here, let me try to help.
First, I want to thank you for sharing your medical challenges. Coincidentally I've also had quite a bit of back issues my whole life, and it seems to he getting worse. I'm at the age now that I'm expecting some sort of surgury is in my future if I want to stay active for another 20-30 years. Congratulations on your 100% pain reduction after recovery. Having designed quite a few products in that space (surgical navigation systems, bone drills, taps and screws, etc) I know from personal experience that that orthopedics is a pretty brutal thing, that's why they cannot Ortho surgeons "mechanics". So thanks for that. Here's to you and your continued health, and hopefully when the time comes for me I have a similar result. You've given me hope, that's one of the greatest things one can give another - thank you.
On to getting you turned around.
1 - I mentioned my career in medical devices because you menrioned in your comment the seriousness of OPs work and that if they mess something up people could die. I've designed high volume disposibles that are made in quantities of hundreds of thousands, also capital equipment that has a typical life span of 5-10 years. If a mistake I made gets all the way to the patient hundreds, likely thousands of people could be harmed or killed. (See the Phillips ventilator stuff currently in the news). That being said, in highly regulated spaces like medical, aerospace, cars, etc. if such a mistake made it all the way to the customer, it's not typically viewed as a failure of the engineer that made the mistake, but as a failure of the company process'. There are tons of checks and balances built into the system (by law) such they there has to be a real systemic problem with the company, it's culture and processes, for a mistake to result in harm. Again, see the ongoing phillips thing.
2 - I have also spent much of my career in small teams, often less than 10. Still, in these cases, people get to take care of themselves without fearing for their jobs.
3 - Precisely because of the importance of the work is why you want a veteran engineer like OP. In one hour of work they could identify and resolve an issue that may take less experienced engineers a month for find and solve. I know because I am that guy, and do it weekly.
4 - Space X is not a small team, they have thousands of engineers, they shouldn't operate this way, and your analogy to your small team doesn't hold in OPs case.
5- IMO you in your situation should run a slightly less lean team that allows for your employees their humanity. If you can't, you don't have a viable business plan and should get anothe r that affords your employees their humanity.
Thanks again for the hope, I wish you the best with your health moving forward.
This (OPs situation with space x) is simply bad management. Criminally so.