For the OP, is the issue pulling the slide? or is it the recoil?
For those who have trouble with the slide, I've heard great things about the Beretta model 86 .380. It has a tilt barrel, so you can load a fresh magazine, tip the barrel up and insert a round into the chamber, tip barrel down/lock it into place, and you are good to go.
No pesky pulling on the back of the slide to load the chamber.
IF it is recoil, then this won't help.
For the 1911 .380, I went with the Star Model S Super. It is more like a 75% sized Model B super- 1911esque, but not a 1911.
For those wanting .380s that are soft-shooting, I have to say that the softest shooting ones I've had the pleasure of trying were the CZ model 24 handgun [delayed recoil, as barrel rotates to unlock. This absorbs some of the recoil impulse] and the Husqvarna 1907.
The CZ was designed to use the 9x19 round, but the Czech govt wanted it in .380, so it was downgraded.
Then, 3 years later they changed their minds and asked for it in .32acp, so the Model 24 got a new upper and conversion parts to allow the same lower to work with the .32 round- but now in blowback. This was the model 27.
The CZ is small-ish, but still is easy on the hands.
The Husqvarna is an FN 1903 with a 5" barrel, made under license for Sweden. [The FN1903 was sold here as the Colt 1903- non-competition deal between Colt and FN.]
It was originally chambered in the 9x20 Browning Long cartridge, which made around 300 ft/lbs of ME in the original factory loadings.
When it was imported here, a large number were converted to the .380, as it was easier to find.
Since it is so large, and was designed for more power than the .380, it is remarkably stable in the hand, with little recoil.
The only drawback to these two for me is that the sights were 'normal' sights, as designed before 1925. Also known as sights that my old eyes can't make out half the time.
The Walther PP in .22lr sounds like a good fit for your needs. However, if it is the operation of the slide that is the issue, I'd look into the tilt-barrel Berettas [made in .22lr, .32 and .380. ]
Now, if I lived out of California, I'd also look at the S&W Shield .380EZ, as it was designed to be easy to rack the slide. My father and his gal [live in Oregon] love theirs, but I haven't had a chance to play with one yet.
just some random thoughts.
The Star Model S Super is also easy on the hand for recoil, due to the delayed unlock it shares in common with the CZ 24 or 1911, but it isn't noticeably easier to rack the slide than any of the others.
Just depends on what the complication is, that your arthritis is causing.