Nausea, Chills, Gastritis, Heart Palpitations, Irregular Heartbeat, Anxiety Related ?

I am waking up nauseas, with chills, gas, heart palpitations, and an irregular heartbeat . I have been to many doctors but they are not finding anything wrong with me. I know it’s not in my head. I’m only 21 I exercise and eat right but I am tired of feeling sick all the time. It gets to the point where I don’t want to get out of bed or eat anymore because I feel so miserable. It’s been going on for over a year and now I’m starting to get used to feeling sick when I wake up and when I go to sleep . I want to know what’s going on and I’m tired of doctors telling me its anxiety . I gave that consideration and tried the things they told me but it’s not working and I truly never believed it to be the case anyway. It’s my body and I will go to however many health professionals I have too, to get an answer to what is causing me to feel this way.