strange chest pain

[cm03]

I have been having chest pain for maybe 4 months now,  it was almost continuious for the first 3 months...feels like a  heavy pressure on my chest, and at times it feels like a squeezing or even a massive throbbing inside the upper center of my chest,  it does NOT get worse with exercise,  and I have a very high exercise tolerance for my weight (250 lbs 5'10,  30 y/o male),  but I can do cardio all day with a peak pulse I can go to 180  bpm without any increased chest pain.....    I have have an echocardiogram, chest Xray and multiple EKG's, holter....No dice .    But lately I have noticed that my past history of mild gastritis is trying to come back on and off again and I have been gassy as in burping  and when I burp stomach fluids try to come up into my mouth,,, even though I really dont feel heart "burn"  does this sound like I have a purely gastro problem?
I have randomly expelled yellowish mucus which appears in a peculiar spotty fashion meaning it always comes up not in one big lump of mucus but several small blob  within the same batch of foamy saliva..
I have no obvious edema,,  sometimes i feel breathless like the wind is knocked out of me
One thing though that really confuses things is that I do seems to have chest palpitations often now but I had one with the Holter monitor on and it didn't show anything wrong there?  It lasts for hours, or even days or a week at a time   (the chest pain),  and burping makes it temporarily better,  I do have a small sliding hiatal hernia too...I had an EGD a few months before this all even started since I was having gastritis, but nobody said anything abotu my esophogus being abnormal,  is it time for a new gastro consult  or should I have more cardiac testing like a streess echo or cath?  One doctor did tell me I had a small murmur over on the left side of my chest somewhere under my armpit though but he said no big deal..

[Cleveland Clinic]

Your symptoms do not sound cardiac in nature at all.  

[Cleveland Clinic]

I don't think that you need any further cardiac testing at all.  GI doctor might be helpful in terms of the hernia.