Well one of my XBL friends found out that it's a bug and Microsoft is fixing it.
Currently they have fixed the problem of my achievements being gone at my profile it shows my correct gamerscore and all the games I've played the only problem is now that I cant see them when I select a game XD (They all appear locked)
And Absolute Dog There is no reason to not play on your xbox I guess they will all return soon... I appriciate your concern