Acer Aspire V3 722G Multiple problems following a BIOS update

As I wrote in the title,I have an Acer Aspire V3 772G notebook and recently it has been acting strange in terms of overheating and stuttering eventhough I clean it regularily and it should not be doing any of those at all,I keep everything up to date,everything but the BIOS that is,so I searched around I discovered that some people got rid of those same problems with a simple BIOS update. So I decided to do the same,found the right download,made sure that it was for my model,but I must've missed something because after the update was (seemingly succesfuly) done,the laptop rebooted but after Acer splash screen a message appeared that said 'Default boot device missing or boot failed' and after pressing Enter it takes me to a screen where I should be able to choose a boot device,but there are no devices to choose from and the only way to get out of this is to unplug the laptop and restart it. After many hours of trying to figure out why the update failed and how to recover the BIOS and either try to reinstall the newer one of roll back to the older one,I accidentally found out that I was able to access the settings part of BIOS,where I could see information about laptop itself and BIOS (oddly enough,it says that the version is the newer one,1.15.) and other settings like boot device order and BIOS password,but some options are grayed out and unaccessible to me (e.g. factory reset). So right now I have no idea if I messed up in the first place or if this is something completely different (since I wasn't able to find one person that had the same problem) and would be very grateful for any help. 

Thanks in advance