Sorry to hear you are going through a tough time, OP. In large part, I'm with blinx7:
Thank you for being there for your mom during a difficult time. I know things must be really difficult right now.
Things will get better, in the meantime just try to do the best you can. I hope you aren't falling behind on bills, racking up credit card debt, etc. but if your savings rate drops for a temporary period sometimes that is just what happens.
Anyways I agree with the above posters but try not to put too much pressure on yourself right now other than taking things as they come.
The philosophy espoused on this site is largely about optimizing, but it feels like sometimes we forget that the reason we optimize and save is to have wiggle room, to have freedom and relief from stress. A crisis that lasts months certainly feels long (I...kind of know, though in my situation it's far less of a personal crisis), but in the end even months or a year or few years of your life is still a small part of your life (and earnings).
That said, some things I might try, or have tried:
Meats:
-Frozen, grilled chicken or steak pieces. You can buy them refrigerated or frozen. Not as good or as tasty as you'd do yourself, but ok for topping a salad or throwing in soup.
-Ham steaks (refrigerated)...cube it all at once and then toss on things.
-Shrimp aren't the cheapest, but they cook in a minute or two from frozen, so a quick way to add protein to things (like the simple soup, above).
-I used to get pre-seasoned tilapia and salmon portions I could stick in the toaster oven (I think they even came with a tray?) Not breaded.
-Frozen meatballs are often quite good, too.
-Rotisserie chicken+any of the above veg options make a decent couple meals.
-Eggs! Scrambled with anything, sunny side, hard boiled...
Vegetables:
-Bagged salad mixes...not just the greens but all-in one. Zero mental energy required (I like the kale, brussel sprout, cranberry ones, but there's lots of options for different tastes and variety)
-Pre-cut/trimmed vegetables like broccoli, green beans, etc. Just grab a handful and steam in the microwave for 1-3 mins. If you can get a microwave steamer it comes out even better...
https://www.amazon.com/Sistema-Microwave-Cookware-Steamer-13-625/dp/B005D6XZ4O (We got ours at the Asian grocery store for $6)
-Frozen veg steamable packets (I am not a big fan of frozen broccoli but many people are ok with it)
-Frozen vegetables+broth (boxed, better-than-boullion) or a simple soup (tomato, cream of ...) makes...a darn good soup. Add meat as desired.
Most of these are not the cheapest, you won't get to a $200 grocery bill with them...but they are cheaper than takeout, and you can pick up a bunch at once so you don't have to get food every day. You can also very likely get them delivered with something like peapod, instacart, amazon fresh, whatever operates in your area? I haven't used these but I've heard people swear by them!
Best of luck! Hang in there.