what might be causing my chest pain

allright where to begin? well i am 24 year old male i am a lil overweight but i have been eating healthier and losing weight!and i do smoke(trying to stopt) i do have family history of heart disease more on my fathers side. about a month ago i started having chest pains and and got freaked out so i went to the ER they did a chest xray,ekg and they came out normal, then did blood work and i have high tryglycerides and cholesterol,so she rec. a stress test i had it done that came back good, went to the doctors and she said it might be bad heartburn(i never had it befor) so she told me to take prilosec i did and it helped, she also said it could be stress and anxiety because i have been constantly thinking that im gonna die and theres something wrong with my heart! so she put me on citalopram(dont know if i spelled it right) for a week and half now my anxiety  seems to be a little better now i still have been having pains on my left side right under my breast sometimes above it ,sometimes the pain will go from under my breast to my lreft arm usaly stops at the elbow, up the side of my neckand across my jaw, and also on occasion into my back by my shoulder blade! oh yea and a few times my groin  my doc said i might have a pinched nerve cuz the pain only last about a min. sorry it was such a long story but i didnt wanna leave anything out hopefully somone can help me or rec. anything thank you!