Garry's Mod 13(ver. 14.01.22) won't let me connect to my cousin's account.

[ThatCooperGuy]

For the past few weeks. I've been trying to connect to my cousin, Andrew's, Gmod server. It keeps "failing after 4 retires".
Andrew and connect with his other friends, but not me. I'm even using Hamachi to connect and it's not working.
What do I do? I looked up how to fix it and none of the threads I've come across are helping.
It really doesn't help that they're all almost out-dated(Like, Gmod 10 or 12)
This is pissing me off...

The current version of Gmod I have is 14.01.22.
What do I do?

[Da Space Core]

This is in the wrong section, anyways, can you connect to other servers? make sure you firewall is not blocking anything

[ThatCooperGuy]

[QUOTE=da space core;43656998]This is in the wrong section, anyways, can you connect to other servers? make sure you firewall is not blocking anything[/QUOTE]
Yes, I can connect to other servers. I can't connect to my cousin's though. We even tried the Firewall thing.

[ThatCooperGuy]

Nevermind ,I got it working. Had to reinstall Hamachi... I'm stupid.