Ghast and Blaze fireballs kills players multiple times and sends player back to original spawn on realms.

I was exploring the nether for the first time in my new survival realm and spawned right near a Nether Fortress. But then when a ghast hit me, they killed me multiple times (about 3 times) and after that was over, they reverted me to the original spawn point. I thought this was only a one time thing, but it was every time and blazes did it too. Please could you fix this nauch. EDIT: I died in lava in the nether and the same thing happened agian please fix nautch