I am really confusd about myself at the moment?

hi in the past week i have been getting really bad head aches and its like 30" here in london and i keep sweating and getting bad shivers and feeling freezing cold, i also cant eat, i try to put somethinbg into my mouth as i am starving but once it gets in my mouth i fel really ill and sick, i also smoke and for the past week i cant do that either i have no interest in them, everytime i think about a fag i fell ill, i no im not pregnant as i have been trying to get pregnant for 4 years and as yet nothing and just come of my perid and done a tet and negative, plze someone help me i hate feeling like this, thank you