Why does my chest hurt?

Today i experenced like around my chest area it had a small pain then went up to my right ear and had a headache like when i was in the car and right now i was eating sushie and my chest hurt real bad when i swallowed it...and now it hurts..and when i swallow...lateley like everyday since the beginning of the year my back has been hurting....then like up to november or december ive been feeling nausea headaches diareaah m stomache has been like churning and feeling like i wanted to vomit...i went to the doctor and she said i have stress...but idk if thats the reason..can you help?