In 1.18.2 forge version, even if I run out of stamina after swinging with my sword, I still can attack with the same sword.

Also if I reached 0 stamina and then rest a bit, and swing again, stamina doesn't drain. Just freeze at the same place

That is expected behavior. You should still be able to swing your sword, but a weakness effect should be applied.

As for the reaching 0 stamina issue, that should also be expected behavior. When your stamina reaches 0 it will be in a depleted state, and will then recover to full, but performing any action during this time will pause the recovery period instead of draining it. This is by design and how the stamina system works in the original Paragliders mod.