Am I okay?

I'm a little concerned about my body because I stopped smoking cigarettes a few days ago and I believe that's why my body is reacting this way but i wanted to be sure. Today I got a really bad headache and I started coughing, it also hurts really bad in my chest when I take deep breaths. My gums are sore and I don't have an appetite to eat. Does anyone have any idea what's wrong with me?