macbook air 2013 stuck on 10.8.5 software

A few programs on my computer stopped working when I updated to macOS 10.12. So in an attempt to reverse the update & go back to 10.11. I erased my hard drive and reinstalled the factory OS which is 10.8.5. Now it’s telling me there are no more updates for my Mac & when I go online it tells me “this version of OSX 10.11 cannot be installed on this computer”. I have no clue what to do.