My phone turned off during data transfer & phone wasn't backed up.

While doing my data transfer from my old droid to the new Galaxy S8 my phone turned off. Unfortunately I wasn't able to backup my phone prior to this so I'm curious as to whether I have lost all my stuff from my old phone. If so is there any way I can get it back? My new phone was able to grab some stuff that was backed up years ago but I'm more interested in getting everything transferred.