what is wrong with me?

Get a D-dimer blood test what you are having sounds similar to what I had. I have multiple pulmonary emboli and they missed it for ages and it became very bad. ECG, pulse oximeter and chest X-rays do not show up PEs. The only thing that will show them up is a CTPA scan. Are you on the pill or any hormone treatment? Or do you smoke?

Have you had your stomach looked at? I had severe left sided chest pain so much so that I was taken into hospital for a week thinking I’d had a heart attack, had so many tests for my heart all normal turns out after months of the most awful worry and panic attacks I had an endoscopy and they found I have a hiatel hernia causing the chest pain and gastritis I literally cried with relief, might be worth getting your stomach looked at best of look to you hun 

I cannot take Zoloft. A doctor I used to go to kept trying different medications for my costochondritis. The Zoloft made me feel pressure in my chest, and I had to go to the ER because of it. Now I’ve been dealing with on-and-off chest pain for the past month. I went to the ER, and after all the tests they said everything was ok but to follow up with my doctor. I went to my cardiac doctor, and he had me wear a seven-day holter monitor. Of course, I didn’t have the pain during those seven days, but I’ve been having it since turning it back in. It’s very frustrating not knowing if something is wrong.

I have been suffering from pretty much non-stop dull, diffuse chest pain for almost two years. I've had a D-dimer test (low so PE was ruled out), an extensive cardiac workup that basically says my heart is fine other than paroxysmal supraventricular tachycardia. I have occasional palpitations - not severe  and not all the time - and have seen several cardiologists. None of them are concerned about the tachycardia so no treatment other than learn to deal with stress. I've been told my issue is anxiety and I'm taking Lexapro (no side effects) which chilled out the constant worrying a bit, however, the physical symptoms/chest discomfort continue. My PCP said I have costochrondritis, the pulmonologist that reviewed by pulmonary screening said normal lung functions and NOT costochondritis as that's an inflammation and wouldn't last this long. I am at my wit's end trying to live with this constant chest discomfort, not stress about it (yeah, right) and learn to live with being in pain all the time. Oh, and I have a family history of heart disease (mom died before she was 65 due to aortic aneurysm and advanced athersclerosis.) And they wonder why I worry? 

I hope you get some answers, Abigail, and perhaps those might shed light on my own situation. If you're anxious a lot, you might ask your doctor about Lexapro. I did not want to take meds for anxiety but I have to say, it has helped. I'm on a very low dose (10mg) and worked my way up to it gradually from 5 mg without any side effects. 

Good luck and I hope you are feeling much better very soon.