My Gmod keeps crashing on and off

So, about 4 months ago I had been playing gmod for 2 months, but then it suddenly started crashing over and over again. I decided not to get help (I’m kinda lazy) and just forgot about it. I’ve recently started playing again and it’s been running fine for about 3 to 4 weeks, but it has started crashing again. It runs fine for about 15 minutes after start, but then sometimes, it starts freezing for about 10 seconds every few minutes or so, but most of the time it just freezes for a second, then crashes. I’m not very tech-savvy, so please make any possible fixes detailed. Thanks!

The easiest way is reinstall it and try it again. Maybe first you can search for problems in garrys mod:
go in your steam library -> right click on gmod -> characteristics -> local -> search for problems.
Hope it workes. Tell me if not