My Minecraft keeps crashing.

So my minecraft keeps crashing.
I'm on a server, hosted by my friend, and it used to be alright playing over it but since I have the new version, it keeps kicking me off and saying that there isn't enough memory to play the game even though before the update it was perfectly fine.
It's really annoying as it kicks me out and I have to sign back in and everything. Then it works okay. Then spazzes out and glitches and kicks me off.