I don’t know how, but my mom could open jars better than me when I was a foot taller and much stronger than her. She’d make me move furniture around, and I’d hand her pickle jars.

Doesn’t help you now I’m sure, but I’ve found gently banging around the rim of a jar on the concrete outside usually loosens the seal enough to open the jar.

(Outside on concrete because I don’t want to dent anything inside.)

Or just stick a teaspoons other end under the lid, prefferably where the thread begins, lever it up a little and it’ll pop.

Yep, I use the end of a butter knife. You’re fighting the pressure that built up rather than how tight the lid is screwed.