nether bug

when I created a nether portal in creatuve it teleported me to the nether but everything was a cave system. I tried digging but netherack was everywhere. I could barely see bigg patches of air. so I teleported back to the over world then it sent me ibto a cave system in the over world and I could not leave the nether portal I was stuck. I had to make another nether portal that's why I got stuck because the first one I made I broke in the nether. but I had to delet my huge castle world that I created. why!