One thing I can tell about testosterone, well at least in my case, is the circadian rhythms. If I go to bed always at the same time of the day and sleep 7-8 hours my body tunes up.
If I start to have random times of going to bed my body and libido goes away along with morning erections and get a bit depressed.
Specially in my case because my work is on a time zone minus 5hours from where I live. SO if today I go to bed at 10pm, tomorrow at 1am, next day at 3am and ocasionally the nex next day I go to bed at 7 am, at the end of 2 weeks, my erections libido sense of wellbeing are gone for good. Than I need one week of regular circadians to restore general wellbeing.
People who work in night shifts are never okay. Ask them, this is true. low libido, depression, etc etc.