One of the reason of your tiredness and weakness could be lack of water intake. Many of us don't drink enough fluids each day and only believe we are dehydrated when we start to feel thirsty. Which is not true according to science. So,  it is suggested to drink at least 10 glasses of water in a day to avoid these symptoms. Keep on sipping the water in such  a way that you can complete this recommendation. You can even include 2 to 3 cups of green tea.

Hi Your symptoms implies that your diet is devoid of balanced nutrients. If your diet is not healthy and balanced then your body Start showing the signs. You need to follow a very healthy balanced diet for healthy you. As at the end of the day you are what you eat so meet a Dietician/Nutritionist for a personalized diet plan and for  assessment that what is Missing in your diet which is showing symptoms like that.