Unexplained nausea and gagging with throat tightness and irritation

[Jay0081]

Hello to everyone, i am a 19 year old guy and for about 3 months now (soon to be 4) i have had a very strange problem with constant nausea and gagging. Could this truly be related to GERD or LPR?
This might become lengthy as i will try to explain everything in detail, but i would very much appreciate any thoughts. This interferes with my daily life and i am so frustrated with it.
Before all of this started i was very active, working out at home, swimming, and kick boxing training. I stopped most activities for one year because i had to focus on schoolwork and finals but i never stopped working out. (simple bodyweight exercises, pushups etc)
But after i had finished school and started relaxing at home problems started.
I refer to my feeling as "nausea" because it sometimes feels likely that i am close to vomiting but more than often i actually really only feel like i need to gag and i usually do.
I will list as many of my symptoms as i can before i get to the part about GERD.
When this all started i did not experience any other real symptoms during the first month. But my "nausea" and gagging was very intense. i would gag during the day almost every 5-10 minutes and it would last for a few hours until it eventually died down, only to return without explanation during random hours of the day. It would happen regardless of what i would be doing and it would interfere with my daily activities. At first i thought it was related to eating, but later i realized i would feel it regardless of whether i was eating or drinking anything.
I tried to ignore it for one month but then i couldnt anymore and decided to check it out at the doctors. I had an echo scan done on my entire abdominal area and i was told nothing appeared to be wrong in terms of swelling or lumps etc.
Around this time i suddenly started experiencing a tight feeling in my lower throat, on both sides of my neck.
Also a feeling as if something was stuck in the middle. I mostly felt it when i swallowed.
I explained these things to a few doctors including my nausea and gagging but most of them said it was due to anxiety or stress. I was given antibiotics (amoxicilin) for my throat because i was told it appeared a bit red or irritated. It seemed to help a bit but the tightness remained.
Eventually i kept checking and i was finally given multiple blood tests, urine tests, and even an upper endoscopy.
All of these tests i was told returned with good results and nothing appears abnormal. I even had a biopsy done with tissue samples from the endoscopy and those returned with good results as well. I am constantly being told that this problem has nothing to do with my stomach, as all appears to be fine.
About 3 weeks ago i started feeling better and worse at the same time. My gagging and nausea reduced dramatically. i would only feel it maybe about 2-3 times a day randomly with no explanation, but at the same time my throat started feeling a lot worse. The tightness increased and it would feel randomly itchy/scratchy. I then would experience a burning sensation in my throat and chest. The burning was terrible and after the very first night of experiencing it, i visited a throat specialist and she diagnosed me with GERD. I was prescribed a proton pump inhibitor. 40mg of Omeprazole. After that i didnt experience a burning sensation in my chest again. So yes, basically i experienced what my doctor thought was heartburn, but for literally one night only. I had never in my life, ever experienced anything similar or any form of heartburn and could basically eat any and everything i wanted.
The itchy/scratchy throat lingered for a while longer though.
So currently i am still suffering from random nausea and gagging. But it is very minimal and random. Sometimes if i relax the entire day, i can go 24 hours without a single gag or nausea feeling. But i notice that my nausea and gagging reflexes come on a lot stronger and intensely while i am active. (long walks, basic house chores, moving around for a while etc) after my gagging has subsided, and i begin to rest, i notice my body feels a bit shaky. only a tiny bit. as if it has been weakened from the gagging experience. But during my rest my nausea and gagging subsides almost completely for the day or until i begin doing more "strenuous" activities.
Over the past 3 weeks the tight feeling in my throat has become a lot less. i definitely still feel it a bit, but it is not extremely uncomfortable as it was 2 months ago. I am currently on a second round of antibiotics as well, prescribed by my throat specialist. there is no more burning sensation in my throat either.
The one other troublesome symptom i have (this one is the most uncomfortable and "painful") is that i cannot speak with a normal tone of voice for more than 20 minutes without feeling discomfort. If i continue speaking my throat feels suddenly very tight and contracted. My neck itself feels stiff and numb around all sides and there is pain in my throat area until i stop talking and rest my voice for a long time.
So that is basically it. I am still taking the proton pump inhibitor medication, along with antibiotics. I havent experienced any other symptoms apart from everything i described here. I have no coughing, and i have never once actually vomited through all of this. My throat specialist says apart from some redness and simple irritation which is was prescribed antibiotics for, nothing else looks abnormal, no scarring, swelling etc. in my throat.
These feelings are rather uncomfortable though, and makes me nervous at times since it has yet to be 100% confirmed what my problem might be. I was planning to take up my gyming activities again this coming month but i am nervous how i might feel since my gagging and nausea increase so much from simple activities and chores.
If there is anything anyone can suggest so that i can look into it, i would very much be thankful and appreciative. I'm sure it has been heard many times, but it's the truth, i would very much like to get back to my life. I cannot even speak to people at a meeting or get together without having to stop due to the discomfort in my neck from it.

Could all of this really be GERD or LPR even though i have never experienced it any other time throughout my life? I have so many doubts about that and i worry at times if there is an underlying disease that i should know about. Doctors have told me the fact that i have never vomited throughout all this or experienced any form of bleeding is a sign that nothing is too serious at the moment, but i would like to figure this out before it might get to that point.
Thank you to anyone in advance.