Minecraft major issue - Help needed

It started when i closed my minecraft (1.7.9) and restarted, i went to open my single player world and java crashed. I retried this 6 or 7 times to get it working, each time java crashed. I updated my java and now when i load a world it sends me streight back to the launcher, it also does this when i create a new world. I have tried resyarting and multiple vanilla installs.

_ Last for lines of the dev console that appears after every crash_
[23:06:36 ERROR]: Game ended with bad state (exit code 1)
[23:06:36 INFO]: Ignoring visibility rule and showing launcher due to a game crash
[23:06:36 INFO]: Deleting C:\Users\*****\AppData\Roaming\.minecraf…
[23:06:36 WARN]: Couldn't delete C:\Users\*****\AppData\Roaming\.minecraf… - scheduling for deletion upon exit

Delete then redownload easy

Makesure you delete the game files in %appdata% .minecraft BUT BACK THEM UP especially your worlds if that doesn't work then I don't know what you should do because a life without mc is no life