Engine Error : CMDLCache : out of memory

When i start GMod , its good , i play Prop Hunt , its still good , but when i play GTA on GMod , when im downloading the Data from Workshop for 20 Min , its good , but then The Gmod closed and this think pop out
"Engine Error
Engine Error CMDLcache : out of memory "
http://img405.imageshack.us/img405/3785/errorzg.jpg

Need to fix This T_T Please i really wanna play , some people say give them ur spec
well here is my spec :

Intel® Core™ 2 Duo CPU , E7500 2.9GHz ~ 2.9GHz
2 GB RAM
DirectX 11
Windows 7 Professional 32-bit
NVIDIA GeForce GT 220
Thats what i know …

Please i really wanna play ;; Please Please Please HELP ;;

Get more ram.