Without a car, definitely don't try doordash. I'll briefly touch on 80-hour weeks and then spend some more time trying to offer more tailored advice.

You might be different (not judging, not asking, decide for yourself if the following applies), but most people can work a couple 6-hour shifts every day with a 3-hour lunch/nap break in between. I've known a lot of people in shitty financial situations and a lot of people who decided to work harder up-front to pull out of them (obvious sampling bias, we'll pretend it doesn't matter), and I'm pretty sure that in retrospect almost everyone would prefer a few weeks of discomfort to a few years of stress, lack of resilience to financial upsets, being set back to zero when you find out your surplus is less than what you owe in taxes, ....

Expanding on that slightly, a 40-hour week often roughly covers expenses, allowing for roughly epsilon in savings, requiring tons of effort and time to actually break free. Most people I've talked to in that scenario take years to escape, if they ever do. Life has a heavy probalistic long-tail on its costs, so if you average your costs over a year you're likely to be surprised by how expensive the next 2-3 years are, wiping out your meager savings. Contrast that with an 80-hour week, all the rest is truly surplus (minus taxes). You work 2x the hours, but you make 4x or 8x or more the actual in-your-pocket income after rent and beans and rice and all that bullshit. It's the same sort of argument from "overemployed" circles if you want to read about more details, but it applies even when you just work longer at a single employer.

The following suggestions are basically going to be a set of things you can do for money with a modest amount of stability. If you want to keep your contract, it would be extra hours (so obviously pick the things with higher dollar-per-hour values, don't work too many extra hours if that's bad for you, and try to save the surplus), and if you don't then you'd want to work as many hours as you reasonably could while you look for your next gig (probably software, the way your experience sounds?).

- Dog-walking and dog-sitting (also cats to a lesser degree) is extremely profitable. If you're walking a few dogs at a time, expect something like $30-$40/hr for each (you can walk several at a time, if they get along), more if you're just walking one person's dog. I normally get $200/hr or so feeding and taking care of some nearby dogs. It's hard to fill your schedule with this, but it's probably worth adding in (especially if it lets you drop a gym membership). A poverty-line contract won't allow you to build much of a financial buffer, but adding in a couple dog-related activities gets you another $5k-$15k/yr with minimal time investment. If you're not good with dogs, maybe fix that first (some of your neighbors are almost certainly willing to let you walk their dogs with them if you want practice and exercise), but it's worth looking into.

- In major metros, you can doordash or uber-eats or whatever on scooter/bicycle. Any time you're free and not feeling overwhelmed, throw that into your schedule. You quickly get a feel for local eats that you didn't have before, and even an hour a day is $8k/yr ($20/hr) toward your savings. It's not as good (since it's slower) as the equivalent car versions, so I wouldn't recommend working a ton of extra time to grind it out, but any time you're able and willing it lets you save roughly 1-major-metro-month of expenses per 6 major-metro-months of work (at 1hr/day), and the time flexibility means you really don't have to plan to fit it into your schedule; you just get extra savings when you're able.

- There are similar gig jobs for filling grocery orders, if you don't like the delivery aspect.

- Knife sharpening is an easily and quickly learned skill that pays incredibly well. Much like dog-walking, you won't fill your schedule with it, but per-hour earnings are far in excess of the majority of software jobs.

And so on. A variety of activities either with the property <high dollar-per-hour> (and any hour constraints), or with the property <can-slot-into-my-schedule-with-zero-warning-whenever-I-want> (and not paying too little per hour) can mesh together to let you build the financial buffer you need quickly and start looking for whatever your actual next thing is (good luck on a next startup?) quickly.