Steam

I am not sure what the issue is then.

Try lowering your render distance, but first reset minecraft's memory allocation to its normal amount.

Were you able to play any longer than before?

Allow Minecraft more memory than it started out with, or try to install 64 bit java. This should work. If not, try to get in contact with Mojang via email.

Try allowing Minecraft to only use 200-300 mb of memory. This should fix your issue.