Feeling sad is a call
Whenever you feel down, do not fight against it; since there are actually some personality traits which are correlated to fluctuations in your mind state. Actually, it is known that in a physiological perspective, sadness its a response from your brain to remain calm and think about situations that could have provoked it. Yet, sometimes you may not even be conscious about what caused it; so, you can try to meditate and re think by assessing every stimulation that made you upset in that particular day. If after that you keep just feeling like that, you should then try to enjoy your frame of mind, and even if it sounds bad, try to conceive happiness among those types of feelings, since these comes from what you are.
@ImYosef
Thank you for sharing this with us , so true I agree with every word you said , we might change our perspective about sadness and pain , they have a function to tell us about something wrong in our baddy or life to copy and deal with , they are symptoms not illness in themselves .