Taking damage in Creative, not taking damage in Survival

I spawned a bunch of villagers, and then I started taking damage when flying in Creative. When I was flying, I didn’t even touch the ground yet and I died by falling from a high place. Before that, when my friend hit me, I couldn’t take any damage at all.

I also couldn’t equip anything like golden boots or a totem of undying. When I was in Creative, my totem was used!