Why do I feel that I am going to pass out each time that I am having acidic stomach?

[weslito107]

I am 27 years old male, never did drugs or smoke. Height: 5 foot 9 1/2, Weight: 173 lbs
Only drink occasionally (once in 6 months to a year)
No history of surgery or other diseases.
I like to ride my bicycle and very active

Then one day.....

Symptoms:
Pre-syncope Episodes - Lightheadedness - when sitting down and after eating. Especially after eating
Numbness in my neck(cervical area) that radiates to back of the head
Frequent Burping/Belching
Chest, Shoulder and Neck Pain
Regurgitation
Heartburn
Itchy Throat
Gagging feeling when I cough

This condition started with lightheadedness and numbness when I am sitting in the office at work. So I ignored it because when I stand up it goes away. Then one day that I am feeling the same symptom even when I am standing up and that scared me. I was rushed to the hospital because it was accompanied with SOB, Chest Pain, numbness - oh not only in my extremities but numbness from the back of my neck that radiates to my head. I was sent to the ER and they ran an EKG, BP, XRAY and some blood test. All came back negative. After all this, ER Doctor referred me to Neurologist and ENT.

After couple of days of trying to sched an appointment. ENT called me and stated that after reviewing my files. It would be best for me to see a Neurologist. Therefore Neurologist here I go. So I went to a Neurologist, this time they ran MRI in my brain and EEG. Results came back to negative.

After my trips to this specialists, I have decided to go see my PCP. She is worried as well, thats why she ran a blood work to see if everything is ok. All HbA1c, Cholesterol, Blood Count all came back as Good. They are all good. PCP even told me that I am very healthy and told me that this is all due to stress. So she asked me what else went down during my trip to the hospital. I have mentioned that I have this chest pains that comes and go. ER Doctor just ruled it out because my EKG came back normal. She said that she doubt that I have any heart disease but since she is worried about me she wanted me to go to a Cardiologist. Just in case that Neuro and her did missed something.

Which brings us to the present day. Now I am currently on portable EKG and I am scheduled for echocardiogram next week. Per my Cardiologist,  after listening to my heart and EKG that he run on my initial visit, everything is well. No murmurs or skipped heart beat. He is only doing these tests to be thorough and make sure, again.. To make sure he did not miss anything.

So now that I am in my portable heart monitor, I started noticing something. I noticed that all of these symptoms gets worse due to this one symptoms that never really goes away... and that is that feeling of acidic stomach. Now that I noticed it more, this acidic stomach which also comes and goes makes everything worse. And the weird part is, I even feel acidic even after I am done eating. Before I only feel this acidity when I am really hungry.

Should I rule out the what I am feeling is cardiac disease and conclude that this is a GERD?
OR
if it is a GERD... What is the connection of feeling that you are going to pass out with GERD?