I feel we need to detach ourself for sometime in our daily routine where one does not think about exam, results, future etc. Hobby can play that anchor role as it connects us to self. I have not cleared Mains stage twice and entire routine becomes a vicious cycle where several weeks become unproductive.
The best way to come out of mental stress and vicious loop is to break it by forced discipline for sometime until body and mind gets used to it.
In my case, Getting up early in morning, doing Pranayama and Exercise(For Detachment part), then Following a Routine with good breaks & Hobby as filler works. Then you can take half day break on weekly basis. Limit overthinking specially at night. I know its tough but when it happens start doing any activity like revising notes or listening to some audio etc.
Dedicate a fixed worry time where one can write all sorts of anxious thoughts or stress factors. One can also fix a shutdown time like after dinner, not thinking deeply about exam, results, future etc. Postpone that thinking to next day, else it can affect sleep cycle.
I know it's difficult to follow perfectly on all days as we are not machines, but in medium-long run it should be a consistent routine which maximises your utility & productivity.
