The Minecraft launcher opens, but when I press play, the game doesn't open.

It will load, the bar will get half way, then disappear. It seems like the launcher doesn't want to load the game, but the computer thinks the game is running. If I press play again, it says that the game is already running. Ive tried to reinstall the game multiple times but nothing is working. I bought the game and it ran fine the first day, but the next day it started doing this. Ive noticed that other people are having the same issue, so this seems to be a huge bug. I can speak for multiple people when I say we need to find a way to fix this.