Crashing consistently since pre 6.

Hi there! So up to pre5 it was running very nice. Played MC on this same laptop for many years.. Though, pre6 seems to crash, and crash.. Mostly when I'm exploring new terrain. If I remain in a local area it seems fine. Can't submit crash reports, even when I click the 'view crash report' nothing happens. Checked to see if there were crash report logs in the minecraft/crash-reports folder, and nothing.. But it's pretty much unplayable.