and to add... flash isn't a, "****, I"M GETTING GANKED, FLASH FLASH FLASH!!!!!!111oneoenoen" ability, you have to use it smart, and not spam it right away (which is starting to sound like what you're doing). you need to use it intelligently.
e.g. you're getting ganked, u run to a wall to flash over, but you don't flash right away, you let them think you're going to so they try to cut you off by going behind the wall, meanwhile, you just walk in the opposite direction and didn't waste your flash at all