it is very hard, some fast methods are a gun, cyanide and jumping, but i imagine that if they are constantly watching you they will notice that you have a gun or somehow acquired cyanide.
my advice is to act as if you had recovered to some degree for some time, it may take a while but they will eventually give you more time and opportunities, failing a suicide attempt because you got caught is not only bad on your body but also on the people around you.