Mac: USB install not working
My advice would be to boot back into OS X. Erase the USB stick and follow the commands given here using Terminal https://support.apple.com/en-gb/HT201372

This is Apple's method of doing it and I've found it far more reliable than using Disk Maker X or any drag and drop method. For clarity if your USB stick was formatted as Untitled, the command would look like this:

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ macOS\ Sierra.app


Because you started the command with the word 'sudo' you will be asked to enter your user password, go ahead and do this and then wait. It can sometimes take up to an hour for this process to finish.

Next make sure have a backup before you proceed to do anything. Time Machine to a USB hard drive of equal or greater size than your hard disk will be good enough.

Once the above steps are done, restart your machine with the memory stick inserted and turn the machine on while holding the alt(option) key. 

Select the Mac OS Installer and follow the instructions. If you're going for just a reinstall over the top of your existing files, simply select re-install Mac OS and let it run.

If you're going for a completely clean install (recommended if you're having issues) make sure you have backup of your system first then proceed to use Disk Utility to format your main hard drive (best practice is to call it Macintosh HD). Then go back to the installer menu and re-install Mac OS to the newly cleaned drive.