Non-Stop Crashes/Memory issues since 5.2.4 Patch Level 2

[rainless]

I've had vBulletin 5 running fine for months on an AWS micro server with 1GB of ram. But ever since upgrading to patch level 2 the system will go from having 422 megs free to being out of memory... constantly.

The database has been randomly crashing over and over again and there seems to be nothing I can do to stop it. It started with [ERROR] /usr/sbin/mysqld: Table './pallmallforum/phrase' is marked as crashed and should be repaired

and then [ERROR] /usr/sbin/mysqld: Table './pallmallforum/nodehash' is marked as crashed and should be repaired

But it seems kind of random. I've tried checking and repairing the database but nothing seems to help.

            total       used       free     shared    buffers     cached

Mem:           992        570        422         75         34        226

-/+ buffers/cache:        310        682

Swap:            0          0          0

And then of course in apache2:

[Sat Oct 15 23:44:50.906161 2016] [mpm_prefork:error] [pid 1304] (12)Cannot allocate memory: AH00159: fork: Unable to fork new process

So it's "run out of memory --->crash"

But it just shouldn't be possible. Please assist!