I can't see the main screen of Minecraft!

um..I was actually trying to touch the 'full screen' off but instead, I clicked a wrong button in Video settings! Then, my computer(actually Laptop!) stopped and it became like the screen shot that is attached.

I can only see single player and Multi player buttons!  I can't even touch the Video settings...

I'm waiting for days to play this! I think there is no way I can fix so can anyone help me?

어..저는 사실 마크에 있는 비디오 설정에 있는 전체화면 끄기를 누르려고 했는데 실수로 이상한 버튼을 클릭했어요.. 근데 그 이후부터 컴퓨터가 멈췄고(노트북입니다) 마크 화면 이 멈췄어요! 제가 아무리 시도해도 안 됩니다.. 어떻게 해야하죠? 

   ps. my computer's app locations and the background picture have changed! I don't know what to do!!!!! and another one! I erased it and downloaded but nothing changed...