I scheduled an appointment, but it's still a couple of days away; I would appreciate some preliminary advice on what could be wrong.
First, my medical history:
I am a 19 year old male, 5'8", 198 lbs. Self-diagnosed tachycardia... My heart usually beats quickly at 112-120 bpm. I told my doc about it once, and he listened to my heart and said that it seemed fine to him. I do not know if it always beats quickly... whenever I check, it reads 100+ bpm. I just checked now (after I started getting this breathing problem), and it read 85 bpm. My blood pressure (left arm) when sitting down is great: 112/80. While supine on the bed, the pressure is 108/60. Three days ago, when the symptoms started, the pressure was 80/60 while supine. _Before_ the symptoms started, I recall one time when my BP was 130/90, but that was a long time ago, and I had been running around. I do not have a pulse oximeter at home, so I could not check my SpO2 stats, but I am still alive so I assume it is satisfactory. I am not taking medications at all for anything, and haven't taken any for a while.
When I breathe deeply, I am not able to get that relieving feeling... I don't know how to describe it. I know my lungs are full of air, but I do not get that feeling you get when you know that the air is satisfactory... Ugh, forgive me, I cannot describe my problem well.
The past three days, when I lay down, I find it very difficult to breathe. When lying on my back, the problem is somewhat manageable. After some "struggling," I am able to fall asleep at about 2 or 3 AM. I get overly conscious (I think) about the fact that I am not able to get that "relieving" feeling and thus find it difficult to fall asleep. Here's the weird thing: I get EXTREMELY uncomfortable when lying on my right side. I always figured it was because I am somewhat obese (BMI 30.9), so I started to exercise and work out for 2 hours a day (started three days ago when the symptoms started... kinda late I know). Exercise does _not_ make me uncomfortable; I can exercise fine. The thing is, lying down makes it far more difficult to breathe than sitting up. Lying down on my right side is absolutely terrible. Terrible. I can't breathe at all (or that's what it feels like). Lying on my left side, however, I have no issues, although it's still worse than lying on my back or sitting up. I can breathe better while walking on the treadmill. Yoga / deep breathing helps a bit too.
The problem had a "sudden" onset three days ago at night when I went to bed at 1:00 AM. However, the difficulty breathing when lying on my right side has existed for a week or two before that. That night three days ago may have been intensified by a panic attack, but I don't know for sure.
I do not recall sweating, pain, or any other symptoms. Just difficulty breathing. Shortness of breath I think it's called... I'm still young, so what could be wrong? I still can't breathe easily, even now.