In addition to daily Qigong exercises, here's one area you ought to check out:

Fatigue, low energy, depression are frequently caused by someone in your area who is suppressive. It might be a neighbor, a relative, a co-worker, your golfing partner.....
Whoever it is, examine the behavior of such a person for moments when he/she
1. puts you down
2. casts disparaging remards
3. makes light of your talents
4. makes you feel inferior
5. makes you feel tensed, ill at ease.
6. ignores you
7. doesn't reply candidly and
honestly to your communication.

etc. etc.......
Such a person invades your universe
with negative energy , and you , knowingly or unknowingly are the EFFECT.

Good luck.