Have you resized all of your recovery partitions? ( in case you have more than 1 hard drive) there's a YouTube follow along, to resize your recovery partition. I had to do a little bit of ad living because I had to hard drives. But her tutorial stacks, I did it twice to the one with the smallest partition just to make sure it had enough room for the future. And then I went and got a fresh copy of Windows 10 from Microsoft as if I was making a boot flash drive. And then just used it on this PC. Might have to go from safe mode to do that.
I had to resize my recovery partition earlier this year when everyone was having issues installing that previous update. It has about 800MB free right now... but I can expand it again and see if that helps any.
At this point, I just hope Microsoft is aware of this issue (with 5 pages worth of people having the same issue with this update)... and they fix it in time for the July cumulative update.