Mac Startup

I have a mid 2012 Macbook Pro 13 inch. When I open my mac after it has been asleep for a while it makes the sound that it's rebooting and then I get the grey screen with the startup status bar as if my computer has died throughout the night. But when the login screen comes up I can't type ANYTHING. Sometimes I have to close my computer and open it back up. Several times. I've had to restart my computer because of this. Anyone know what's going on?