For a few months now I was using both Linux Mint and Windows 10 through a dual boot setup and a grub loader on startup. Suddenly this morning I can no longer see my grub loader or any boot options and am automatically booting into Windows. I have checked the UEFI boot options and I can no longer see a grub/Linux option. I currently do not have access to the USB I used to initially install Linux. I am wondering what the best course of action is to recover the grub loader and boot into my Linux partition. I am also concerned that the Data may be corrupted or lost. Any insight on what to try/how to proceed would be very helpfull. I have read a little about using bootrepair after booting using a USB, but I currently don't have access as I mentioned and would like to see if there are alternatives as I require access asap. 
Dual Boot Suddenly Stopped Working
linux;boot;grub