PrI[]\[]CeSs

Hi Im 17 years old. I've been have heard aches and heart burns since the age 15. My parents dont really take it serious lil they jus think I eat to much greasy food (which I really dont eat) or they'll say that I jus been stressin too much (which I know that thats not it). I always get these sharp pains in my heart and he jus ache for a hour or some or long. I really dont know wut it is. I went to the doctor a couple of months ago but they couldnt find nothing wrong with me. They said that I was perfectly find and that nothin was wrong wit me. Not it's starting back to hurt Ive been loosing weigh and it jus hurts on and off im now about 5'5 106lbs. Every think that something is wrong with me becuz Im loosing weigh like this but my parents jus dont see it they jus think it's normal but I feel sickly Im always tired and sleepy. Can anyone give me some type of advice