First of all remove all myths & misconceptions from your mind about masturbation
In fact, Masturbation is completely normal & doesn't have any bad effect to the body and mind.
The symptoms as mentioned in your post can be due to:
1. Lack of certain essential vitamins & minerals in diet.
3. Inadequate rest or sleep
4. Any fluctuations in the blood pressure & blood glucose
Avoid stress...practice meditation
..this helps in improving concentration & builds up the confidence level.
Have a healthy balanced diet rich in fruits, vegetables, fish, nuts.Multivitamin
& multi mineral supplements can also be taken.
However, if the symptoms still persist, it will be better to consult a Doctor & get a proper physical examination done to find out the exact cause.
Wishing you a Healthy Life.