Can't play Single Player or Multiplayer

EDIT: 90% of the time the game doesn't even launch, and when it does, I can't play.

About a week ago when I was playing my game crashed. Ever since then I have been unable to open single player worlds or join multiplayer worlds. When i would attempt to do these things I would be presented with the normal loading screen saying "Loading World Building Terrain", except it never actually loads.

I have reinstalled Minecraft, deleting every last file of it from computer and uninstalling it from control panel. I have done the same with java, more times than I can count and nothing has worked. I seriously doubt it's because I don't have enough ram since I have 5GB of ram free on my computer.

I tried using one of the older launchers, and that actually worked, but it left it resetting EVERYTHING whenever I would try to use it again, so that's not an option. Technic also works, but it's a pain.

I really don't know what to do. I'm desperate for a solution.

Feel free to ask me any questions, or if you need screen shots of anything. I appreciate any and all help. Thanks