Lack of sleep and fatigue
In this case, there is no doubt that if you feel extreme fatigue after taking a break of a day or two, it is definitely a sign that you are overtrained. This can happen because you never give your body enough rest and all that fatigue accumulates which leads to extreme exhaustion.
Some people may even experience the opposite effects. to suffer from insomnia and not to have a peaceful sleep. Make sure you get enough sleep as this is the most important recovery period. You'd rather take a week off from training because that's better than ruining your potential results in the long run due to fatigue.
ZMA> can be very helpful in increasing testosterone as well as regulating sleep