Samsung Galaxy S3 — blank screen almost invisible inside crack, what to do?

Hey guys

Need your help, my Samsung needs your help.

Essentially the screen won't work, it's blank, the notification light is on and the touch buttons are as well. It took me the longest to notice (that's how fine the physical damage seems to be but not the functional one) underneeth the screen protector from within appears to be a crack (well maybe, I think). It doesn't seem to have cracked on the screen on the outside. Tried the "separate the battery, press the power etc" before noticed the crack that is only visible to the eye on some very specific angles. The fact still remains, my phone doesn't work. I see people's screens function with all sorts of ailments... What can I do? Needless to say I need my phone for work and school. Please your advice on a fix will be most appreciated.

Thank you