Bootcamped mac will not boot into OSX but I will into windows

-My mac boots into windows 10 partition but not my mac partition -I have tried to install sierra onto the mac partition via a USB but the Macintosh HD drive says it is locked -I can access my mac drive using HSFE explorer on windows side -I'm using a 1TB 27" 2013 mac -I prefer not to clear the drive

I have made a previous post and since then I decided to upgrade to sierra to fix the startup (I can now go back into windows): https://www.reddit.com/r/applehelp/comments/68nrip/help_mac_will_not_boot/?st=J4082GQX&sh=fd462bdd

HALP PLEASE :D