Constantly being loaded into nothingness when going through end and nether portals. And had endermen attack me when im looking down

I keep getting loaded into nothingness when going through nether portals and when I quit and restart the game, its gets stuck loading terrain. Same thing happens with end portals. In one case, i did it, half the end world loaded and I was apparently near the edge and an Ender men hit me off, and I was just looing at the ground. So endermen will also attack for no reason