Hi, I Haven't Been To A Doctor For A Few

Hi, I haven't been to a doctor for a few years. For the past 12 to 18 months ive been feeling very tierd, also my joints are sore, i seem to bruise easily, I usually have nausea in the morning, i get diroreah alot, and when I get my period I feel extremely weak, i urinate alot, i also have a lack of appetite. Im 27 and have had three children! Whats wrong with me?