Tried to remove add on and broke my world

I purchased an add on from minecraft marketplace and did not like the new mobs so I deactivated it, but everytime I get on to my realm these mobs I do not like are still there but just invisible! Ive tried to delete all the data, cache, and everything else attached to this add on but I can not remove these mobs. I'm trying to avoid deleting this world so is there a way without starting over?