Takes a long time to load into servers, when I load in I get a connection problem

Alright so
When I first start up Garry’s Mod. I can join servers fine.
But when I go to join another server (Or the map changes)
It loads all the adding and stuff. Then it gets stuck at “Sending Client Info…”
After it finally loads in. I load into the server. I hear the game (Like player voices or explosions)
Then it just goes quiet and the, “Connection Problem disconnect in 999 seconds” ,appears.
I got 4000+ hours in Garry’s Mod and it had done this for several months.
Even after I got a new computer it did it.
My internet is great. So it can’t be that.
My internet is AT&T if that helps.
If you require anymore information then just ask.

PC specs?

Internet speed?

Addon count?

You didn’t have good RAM.
Your disk is maybe full?
Clean your disk on C:
Install all applications on your D:
Can you sens me your speedtest on the network ?
Network card didn’t have a good config?