Everytime I decreased my visual setting it maximizes the whole settings at every restarts. I dont know if I used a console command unintentionally. How can I solve this?
Keeping video settings in CS:GO
counter-strike-global-offensive
Related Solutions
You should put those settings in the designed steam option for the game.
Right click on CS:GO -> properties. Select set launch options... and type your settings
Example: 
This will save your settings.
Well, I personally wouldn't make the command say that in chat, since it could be annoying to other players. You could use "echo" instead, which displays a message in console.
But to answer to your question, I don't have a way you would like it (I doubt that you can even check the variable like that in CSGO), but I have an alternative: Bind it for two keys.
F1 sets voice_enable 1, and you could add a message for that to say it's on.
F2 sets voice_enable 0, and it would give a message that voice is off.
If you use
bind "F1" "toggle voice_enable 0 1"
you can see the change in console, without having to add any "echo" or other commands. Just make sure you have binded console to some key.
Best Answer
Installing CSGO with custom HUDs will preload the conditions of the hud everytime you run the game. Some HUDs are more demanding than others, and will amp up your graphics everytime you run it, while some are less demanding.
Just uninstall your HUD, and you should be fine. If you don't know how to uninstall your HUD, an easier fix is to go to the Game Properties option by right-clicking the game in Steam, then click Validate Game Files. This will check for discrepancies in your game client and the actual game, and reset your settings accordingly.