Tired, Dizzy, Pins And Needles In Legs, Headache. Is It Because I'm Getting Older?

For the past 2-3 months have been feeling a little more tired, but I do have 3. children and run around a lot. I feel as if there is something not quite right, at times am nauseous-doesn t lat long and is not everyday (not pregnant). Also I get dizzy-the room goes black a i get pins and needles in my legs and i feel as if i am going to pass out but i never have this is whenever I stand up from crouching or sitting on seat especially if I do it too quick, now again I get a slight headache , not enough to take paracetamol I just drink more water. Would it be because I m getting older? I m a 39 years old female