Dysautonomia w/out POTS

I've had issues for years, my dr referred me to a cardiologist for a POTS workup (which is why I am posting here and not the Neuropathy page). I fit nearly every symptom for dysautonomia. I can't find any specific type of dysautonomia that fits my symptoms other than the general ones. Whatever it is it has been significantly affecting my life. I hate feeling like a medical mystery. It has been years and I can't work more than a few months at a time because of the fatigue and breathlessness...but the thing is I'm not out of shape!

I have a physically exhausting job working in a warehouse part-time currently, but sometimes (not always) I feel out of breath just putting away the dishes. I think my breathing pattern is odd when I'm exercising too. Whether I'm stacking pallets at the warehouse, pushing hard on the recumbent bike, or speedwalking, things will be fine for a few minutes then I will start panting hard, feel very hot, and lightheaded for a few minutes, then breathing will return to normal, then panting again, practically hyperventilating, can't quite catch my breath, then back to normal while maintaining the same pace the whole time. If I push myself too hard I feel a sharp pain in the middle of my chest, instant extreme nausea, feel very lightheaded, and see spots. All of it goes away the second I slow down. It's the reason why I stopped running when I was younger and have stuck to lower-intensity exercises like a bit of weightlifting with dumbbells and regular walking.

I have been waiting for cardiologist for weeks and called the clinic a few times but still waiting on the referral to be processed at which point they would reach out to set up an appointment. I am extremely anxious about my health at this point because things aren't getting better and I want to keep a darn job! It's maddening and exhausting and it's a cycle that has been going for about 10 years now and I have more than had enough. I'm only 26. I need answers. And I am so sick of having disabling symptoms with no explanation or path to recovery.

Compression socks and abdominal compression binder help with the chronic nausea, stomach pain, and memory, but is not a complete fix for the memory and does not always help with the fatigue. Without them, I forget so many things the instant after I have done them, many times a day to the point that it is concerning and has gotten worse, especially the past year but brain imaging all came back normal. Nothing helps with fatigue except rest, but even that doesn't always help. I've started pushing myself to exercise more for heart health as that is a treatment for a lot of these conditions, though exercising or going to work when the fatigue is bad makes me pant/lightheaded much quicker and makes me more anxious about whether or not I should really be working if I some sort of heart or lung condition.

Any thoughts or comments are greatly appreciated. I know no one can diagnose me but if something I said trips your radar I would like to know. I would rather do a lot of research on many conditions it could be rather than be blindsided by a condition I have never heard of during the appointment.