I've lead the bulk of my life this way, from when I was first on my own going forward. I shared your sleep-deprived night last night -- couldn't fall asleep until sometime after 2am, the last time I checked the clock.
I had a single reprieve, back from 1995-1999, when I was recommended for 3 months contract work in another dept. at the company that had laid me off the year before. 3 months stretched into 5 years, and I first doubled and then tripled my old salary. No benefits, but I'd never needed them before (except the health care, which HMO had left me to die when I was seriously ill, so that was no loss only gain).
That 5 years was my only break from worrying about money, but even then I worked constantly to make as much as I could while I could because I knew it couldn't last. I will always be grateful to Al Gore for "inventing" the internet and making the high tech boom possible.
It was also a 5 year break from clinical depression, when I was doing creative work I could take pride in, was treated with respect by management and my clients. Still hated by my peers, but that has always been the case except when they didn't notice I existed.
Hard for me to believe after all I've been through that just when I thought I finally would be secure and have enough income to start paying off student loans and saving again, with combined p/t wrk and social security, the lab dumped me without notice, without even the common decency of telling me themselves, instead leaving me to find it on the schedule.