I have covid and today's the last day to pick up my paxlovid from the pharmacy for it to have any effect, but my car has a flat tire. I've been trying for 3 days to get the lugnuts off, and I just can't get them unstuck. I'm using the shitty 8-inch tire iron that came with my car, and can't get enough leverage. I've tried jumping on it, I've tried beating it with a hammer, but they won't come off. And it's made even tougher by my diminished breathing and strength due to covid.
I've had this happen before. What you want is technically a 'breaker bar' but do what /u/sloth said. Me, I had an old metal corner post from a bed, essentially a long tube/pipe, that the handle of the tire iron went inside and I jerked on the tube. Look around for some kind of long metal pipe!
A "cheater bar." Just be careful, these things can be somewhat dangerous.