Whenever i feel very sad about something, after few moments, my left side of head feels irritated and can't control my thoughts (like going crazy) i've done eeg and tdm normal and am already taking antidepressants but still the same, what could i hav?

It is not feasible to provide an opinion without additional history, physical examination may be some tests. It would be prudent to see your doctor to see if depression is the cause. Counter-intuitive as it may seem, exercise may help. Start with low intensity exercise such as walking and gradually increase the intensity as tolerated. Drink more water. Wish you good health!