SSD or HDD failure..

Windows 8.1 Gigabye h170 mobo Western digital blue hdd SanDisk plus 250gb ssd

While I was downloading something and casually playing games.. I noticed there was an error in my HDD (D:) as my download folder.. The pc doesn't detect it..
Then I restart my pc then there is already a boot error.. When I check the bios my HDD isn't detected by the motherboard but SSD C: is still there. But I can't boot anymore.. It was fine before I restarted..