Its likely a problem with your home PC causing Garry's Mod to crash.
You could always try verifying game files or even reinstalling.
Let us know what works and/or what happens!
Remove all unneeded add-ons and make sure you run menu_cleanupgma or whatever it is in console. Also make sure model detail is set to High as lower detailed models crashes the game, also verify game cache if you haven't done so.