Most likely you didn't properly repaired the device the correct way. That usually happens when you replace the glass and don't bond it with oca (optical clear adhesive) or loca (liquid optical clear adhesive). I've use to do this, when I first started repairing phones. Now I use loca to bond them, making every repair look just coming out the manufacturer as possible.
You damaged your LCD when you dropped your iPhone, but also since you are experiencing more problems. It can probably be some components got damaged on the motherboard. I've seen some couple accidental drops and notice some components were damaged.