Start up problem

Hi. I have macbook pro retina mid. 2015 and i have a very big problem ..

so this is how it goes. I downloaded a windows 10 using a bootcamp and it works well but after a week i decided to uninstall windows10 from boot camp.. and then i am currently using IOS that time and i tried to format it and right after i restart it i show a black sreen and it says that "Recovery your pc/device needs to be repaired" and at the bottom of it "press enter again" "press f8 for startup settings" i tried to press f8 and enter but nothing happen i also tried to restart it while pressing "Option" but when it open only the windows os is my choice. I also tried Crl+R but it leads me to internet recovery but once it start downloading it stuck on around 10% of the loading and not moving at all . Can anyone help me with this please