My Macbook Pro keeps restarting after it failed to upgrade to High Sierra and it shows a kernel panic.

My Macbook Pro downloaded the whole High Sierra 5.22 GB file but failed to install it I don't know why. I've got more than 400gb free on my 500gb hdd. It also shows a kernel panic and keeps restarting again and again and I can not enter the OS. However I am able to go to recovery but I didn't do a time machine backup. Please help!