I was in my survival world and I died but it was like a glitch

I was in my survival world building a dog house for my dogs.  I was stacking up blocks and I went up about 8 or 9 blocks high . I accidentally jumped off the blocks.  Minecraft glitched and when I fell I died  and I lost my 24 levels which made me really mad. I then went back to the dog house and jumped off the 8-9 blocks that I stacked up high. But when  I fell I only lost three hearts and it was really strange.