replacing cracked screen/glass on lg k7

You likely separated a little to far down on the display. Sounds like you removed the polarizer sheet from the LCD which is very much needed to see an image on screen. The digitizer sheet responsible for touch functionality is transparent and is not tinted or darker. Sounds​ like the glass, digitizer, and polarizer were all removed so glass only repair is now out of the question. So like Dylan mentions it's best to replace the whole display assembly at this point. Not a great chance of repairing your current screen unless you refurbish screens for a living and have the correct equipment, which most of us don't. Replacing the whole display may cost more but is so much easier than a glass only repair. Glass only repairs are getting harder with newer devices compared to older ones due to numerous reasons. It's always worth trying a glass only repair in my opinion. I just usually wait to buy any parts untill after I attempt to remove the glass. That way if I damage the digitizer or LCD I know wether to buy the whole display or just the glass with the digitizer already adhered to it. I do give you lots of respect for attempting the glass only as they are a challenge. Very rewarding when they go successfully though. So don't hesitate to try again in the future. Best of luck on your repairs.