I am a 25 year old, active young male. My problem is I am constantly tired & fatigued, I fall asleep without any control at home, what could it be? .

Keep track. A helpful tip may be to keep a log about your sleep (this can be found online) and keep track of your actual sleep time. Even more than medical or sleep disorder, commonly people are not getting as much sleep as is needed. If you are getting at least 8 hours of sleep nightly and feel the same, see professional and have some testing done. Sleeping > 8 hrs and fatigue can be depression, so watch.
? Narcolepsy. Check your life style if there is no cause, sleep apnea or narcolepsy are possibilities sleep study?!