Steam – Auto-Disconnect when playing Counter Strike GO

Since a recent update, you can now set it so that only your friends, or no-one can see what you're playing.

Go to the Steam community settings page here, it can be found at that link or as this answer states, on Steam go to Profile > Edit Profile > My Privacy Settings > Game details
At Game Details you can choose between public, friends only or private.

This category includes the list of all games on your Steam account, games you’ve wishlisted, your achievements and your playtime. This setting also controls whether you’re seen as "in-game" and the title of the game you are playing.

From what you say, i understand that you open torchlight shortcut and then it opens steam. If this is the case, you should open steam separately and leave it online, then open the desired game ( Torchlight 2 in your case ) and it should work fine. If it goes offline mode on its own it's a network issue and you should check your internet connection.

EDIT:

I thought it's obviously that those issues are the result of a poor internet connection. Perhaps you can try :

1. Exit steam. Delete everything from steam folder except steamapps folder and steam.exe file. Relaunch steam and it will make all the updates again (it will take a while) and check if it acts the same.

2. Try a complete reinstall or steam (you can save the steamapps folder somewhere on your HDD so that you don't have to download every game again or lose save games etc.

Other than that it's purely an internet issue.