Headache and temperature has nothing to do with your activity. Feeling weak could be a possibility as ejaculating semen quite often means loss of some minerals from your body - such as zinc, protein, calcium, blood group antigens, magnesium, sodium, potassium and other nutrients. (this will be a concern if you are addicted to this activity). Masturbation is a common activity. It’s a natural and safe way to explore your body, feel pleasure, and release built-up sexual tension. It occurs among people of all backgrounds, genders, and races. Despite the myths, there are actually no physically harmful side effects of masturbation. However, excessive masturbation can negatively impact your relationships when you get married, you will feel more pleasurable masturbating, than having real intercourse, as you would have reached the stage of chronic masturbation. There are ways of cutting down this activity, divert your mind and do something productive, go for a walk, hit a gym, step out of your room or house and spend time with your family, friends etc.