My horse turned into an alpaca , changes us form creative mode into survival mode, sent me down to a place, peaceful mode

Suddenly my horse turned into an alpaca , and then suddenly, liking likes turned us from creative mode into survival mode? And just now I was clearly at home, not touching anything, and you sent me down to a place I don't even know where? Why am I getting zombies in Peaceful mode? And why did I suddenly switch from Creative to Survival mode? This has happened several times, even while flying in mid-air - I just drop down suddenly. And when fighting the Wither and the Ender Dragon, it suddenly switches to Survival mode and kills me.