All durability is physical. Endurance of the body is also physical.
Tsunade summoned Katsuyu and healed the Kages while being cut in half without using any sort of medical ninjutsu to nullify the pain. So what do you mean that ain't physically durable?
Also, Durability is applied for non-living things. Not for living things. If you want to apply durability to living things, then you are talking Endurance.
the way I see it is that: endurance often reflects on what someone can withstand mentally (ex. pain)...durability is what someone can withstand physically (ex. attacks)
If someone got hit by a TBB and they got knocked out by it yet there isn't a scratch on their body then it's durability
If someone got hit by a TBB and still stood afterwards yet their body is extremely damaged and bleeding then it's endurance
If tsunade was physically durable to an extent then she would of never got cut in half...her body would of still been intact to a degree. Similar to how the 3rd raikage was after being hit with rasenshuriken...but since she was cut in have and still managed to push and heal herself despite the pain it can be considered endurance...
both are similar words but with very different meanings