Blocks Just Disappear

[architect-1]

Hi, I've have been playing some Hexxit with two of my friends. The server doesn't seem to be the issue and it is only me its happening to, so I'm assuming it is client side. Anyways for a couple hours now, after playing for about 15-20 minutes, everything disappears except for stuff such as bibliocraft tables and lamps. I can move around but everything is see through except for particles (and bibliocraft, previously stated). And no this isn't the problem because it was the blocks were disappearing well before this. But anyways, I placed a meteor shield down and noticed it would should out a yellow light (I'm assuming it is destroying a meteor or something) about ten seconds afterward my minimap will go blank, there will be some lag and thely blocks will disappear. Though I just noticed recently, when I try to log out or disconnect, all the tabs are gone, just words. All the entities in the NEI are gone except for the blocks I can see. And what worries me is when I go to the title menu, the tabs a missing similarly to the options and there is no title screen, just the flashing options screen I was previously on and only the random yellow message is bouncy. Even worse, when I try to close hexxit it freezes my comp. I have to manually shut it down and reboot. So if you could please help that would be nice. Also, sorry for the wall of text, first time posting.