Crashes every time

Every time I launch Minecraft, it fails. I have made my skin, uploaded it, watched tutorials on how to launch it if it crashes, payed the full £20 and my computer is only 3 months old and it still crashes every time. Please message me if you can tell me how to fix this, let me know. I absolutely love the Xbox 360 edition and I really would like to be able to play PC edition.

Thank you for your time.
<3