My minecraft wont work after i have launched it (the launch screen will come, but it gets stuck there)

Hi guys,

I played version 1.6.2 for a while now, but recently a problem occured randomly.

When i start my Minecraft, the first part will work (with all the notifications and stuff of what is downloaded and what not etc.). When I get to the second part, my Minecraft sort of crashes. Everything that I see is 'page loading...' and on the bar below i cant clik 'play (play is not clickable or visible). And my account info on the bar right below keeps loading. My computer also crashes after a while and i can't close my Minecraft.

PLEASE HELP!!!