Bloated stomach - hard to breathe

[whatever54]

For about a month now I've been experiencing trouble breathing. At first the breathing difficulty occurred when I was going to bed. Just as I was about to fall asleep it felt like my body just stopped breathing or was about to stop, so I had to wake up and take a deep breath, and after that I felt food being digested in my stomach, which kept disturbing my sleep and I had to stay awake for like an hour or so. Now the breathing difficulty during sleep stopped, but I'm experiencing it while I'm awake, and it lasts all day long. I'll try to write my symptoms down below:

-When I breathe in, it feels like I'm not getting enough air, or the air that I'm inhaling doesn't reach my stomach, just fills up my lungs and expands my chest.

-I can take a "normal" deep breath through my nose if I do it manually, but my nose is congested and usually I mouth breathe.

-I don't feel any pain in my lungs or the stomach itself, I have no coughing or wheezing symptoms.

-I've only experienced chest tightness once, while I was asleep, I guess I stopped breathing that night because I was half awake half dreaming, and my chest got really tight and my heart was pounding fast, but then I woke up, gasped for air and the feeling was gone, I just felt really scared, so I walked around the house for a bit, went to the bathroom, had a glass of water, felt a sleep an hour later.

-I'm not experiencing any heart palpitations or fluttering symptoms. Although I had it in the past, when the doctor checked my heart he said that there was something with my right valve, it didn't close properly sometimes or something like that, but I was warned not to worry about it, because according to him this happens to tall kids while they're still growing (I was like ~17 at the time, 6'3).

-I can breathe easily when laying down, especially if I lay on my left side.

-The breathing difficulties don't occur if I distract myself, or talk to someone, but it's really hard to do because I always think about it, and the moment I do I automatically try to take a deep breath through my mouth.

-Sometimes it's really hard to eat, as soon as I start eating I start experiencing breathing difficulties, which makes it almost impossible to eat.

-I can also breathe more easily if I slouch or squat down.

I'm a 21 year old male, 6'5, 205 lbs. I don't work out but I work 8 hours each day and I'm always on my feet during the time, I also walk to work and back home, so I guess that counts as some sorts of physical activity. I smoke, usually around 12-18 cigarettes a day.

I've experienced one panic attack in my past when I was younger, and recently I had another one at work, but it wasn't as bad as the first one. I thought about my breathing a lot that day, and I think I started hyperventilating because I was taking deep breaths through my mouth, and I got scared, the panic attack kicked in, I started trembling, felt really scared, but I walked it off, went outside to breathe in some fresh air and the attack stopped, after ~10-15 minutes or so, but I felt really dizzy or "high" for an hour after that.

I've read about this a lot and people say this might be anxiety related, but the thing is, the only thing I feel anxious about is the breathing difficulty lol, in general I'm an out going guy, I'm not shy, scared or anything, I have no problem socializing with others and I feel comfortable everywhere, so I don't think it's caused by anxiety, although I'm always anxious about my health, whenever I experience something weird I always google it, read all the symptoms and what not and always think about it untill it passes.

So does anyone know what the problem could be? I'll be visiting my doctor soon, I'll get my blood tested and get an x-ray of my lungs, maybe they'll check my stomach, I'm not sure.