I'm inferring that you have a family to support. (If it's just you, I'd seriously consider declaring bankruptcy.) I can relate. For what it's worth, this can be the lot of men in our society. I don't think it's an indication that you did anything wrong. Good luck.
My condolences on the divorce. I wasn't married but went through something similar. And know that suck the life feeling.
I agree with your last sentiment. Alot of the career seems to be luck or right time right place. I know a number of phenomenal engineers in similar positions.
Vest means become available to sell or trade. You are also given stocks at bonus time. Encouraging you to stay around.
The vesting schedule varies, but probably the most common arrangement is that you get 1/4 of the shares per year for the next 4 years. Often you get nothing until you've been there for a year, then get a whole year's worth of stock in one big lump sum, and then get smaller amounts more frequently thereafter.
In the US, the stock is taxed as ordinary income on the day you get it. If its price goes up before you sell it, you also pay capital gains tax on the change in price that happened while you were holding it. (I sell all my stock immediately on general principle, so my capital gains taxes are tiny.)
Philly Team Lead Architect @ 185k w2 contract with health insurance and a week of PTO
Seattle System Admin -> 115K (There was an intent to promote, but we didn't agree on my career path).