Anxiety Or Heart Problem?

O.K. I am 14 and I have been to the er like 5 times had 5 ekgs, 2 chest x-rays, and echocardiogram where they use the dopplar thing, and a ct scan. I get this constant unrelenting pressure in my chest and I have been diagnosed with anxiety I guess but I don't believe it. Although this did happen after my dad died in september I don't think it is because of that. I get pain in my left arm and stomach problems and really bad chest pain. My mom is getting all stressed about it cause I am constantly checking my pulse or have an asprin in my pocket just in case. I seriously think I am going to jsut die. My doctors said it is not my heart but still, I think the problem I have is undetectable or someting. I even had blood tests at the er and as of 1.5 years ago my cholseteral was only 135 total. This pressure just won't go away. Xanax helps a bit but really just makes me fall asleep and lexapro I started a month ago is doing nothing. I also have a disease called lupus. I am afraid cause my dad had a similar disease and died of a heart problem. I am afraid the same will happen to me. Cause lupus effects your kidneys heart and everything really. I looked it up on the internet and everything seems like a serious problem and isn't helping me being anxious at all.

Do you all think it is anxiety or a heart problem? I think it is my lupus or my heart but my doctors all say everything looks good like my liver kidneys etc except for a liuttle protien in the urine. I have a big tummy but am not overweight, I am perfect for my age they said. Also I get cold hands and feet, I don't know if that will help, but I really think somethings wrong especially since these pains are all the time and get worse.

Anyone else have this? I know this was long but thanks for reading it. :) :? :d