Minecraft won't start, and when it does, it's messed up.

Minecraft worked fine. Then, the new launcher came out. The first time playing with new launcher, it worked. I started it up again, and it crashed on the Mojang screen (the Minecraft has stopped responding thing). I closed it out, and it took me back to the launcher. It tried starting it again, and it took me to the start screen. I tried starting a new world and it crashed during world creation. I went back to the launcher, and started it again. This time, I tried joining a server. It crashed again. I have repeated this so many times, still does not work. Please help. I have tried on multiple versions, 1.8.2, 1.11.2, and the newest snapshot.