Have you tried meditation DiscoDan?
Heres one I would recommend for cultivating positive energy:
"BODY OF LIGHT
- Visualise above the crown of your head a white ball of light, somewhat smaller than your head. It has no real form and is pure white energy. Do not concentrate on details, just try to feel it is there.
- Imagine that the light embodies all the pure love of the universe, the accomplishment of the highest potential of living beings.
- Visualise the ball becomes smaller, about the size of your thumb, and it enters the crown of your head, and descends to the level of your heart.
- Now the light expands and fills your entire body. All the material of the body dissolves into light. What remains is a body of light without shape.
- Concentrate on the feeling this light-body gives, all problems and negativities are gone, only peace and happiness is left.
- When distracting thoughts arise, simply dissolve them in the light."
From
View on Buddhism: (Tibetan) Buddhist practice and philosophy
I always feel absolutely amazing and energized after that meditation.
But to be honest, I think theres some greater and deeper underlying issue thats causing this tiredness. I think it would be wrong to say that what you're experiencing right now is "normal." Mayeb you could scout around more and be more aware when you're interacting to find out the real reason for your tiredness. Good luck!