More than a Handful of Problems with Garry's Mod

[Philososquid]

Hi, I don't even know where to begin.. But here goes

1. When ever I start up garry's mod it goes to a black screen.
2. When ever I try joining a server garry's mod will crash giving me this error:

hl2.exe - Application Error
The instruction at "0x00000000" referenced memory at "0x00000000". The memory could not be "read".

or

can't load lump # allocation of bytes failed

3. When ever I try joining a server It'll be at," Sending Client.. " And it'll send me right back to the menu to choose a server
4. When ever I try to join a server It'll go to a black screen

PC Specs;
Hard drive: 931.50 GB
Installed Memory (RAM): 4 GB
Intel(r) Core(TM) i7 Cpu 920 @ 2.67GHz 2.67 GHz
32-bit Operating System
Radeon HD 5750 1GB of Memory
Directx 9

[Philososquid]

bump?