Depression. Permanent solution.

I was gone through  depressio n. after treatment all symptoms gone but my sleep quality decrease when i left medicine. if i have to sleep i have to follow regular same time go to bed and same time wake up. if i do this then i sleep but quality not good. if i don't do this. i at all not sleep. but the problem i do for some day regular if i missed to go at same time sleep or wake. then next day unable to sleep. then after 4 or 5 days sleep will come on that time which i have missed. again quality good. if one day i missed my cycle the next day i not sleep. which is not possible. i am student because poor sleepi have forgetfulness. i am doing exercise. what should i do  for deep  sleep any effective permanent solution. this was my 3 rd treatment amitriptline and chlorobenza 25 mg for 6 month. i have left this medicine almost 14 month.