My breathing is wierd, is it Acid Reflux?

So about 2 or 3 months ago i stayed up till about 3 or 4 a.m. I was putting olive oil in my hair and about that time it was in for 5 hours. Then i started to notice my breathing was different. I really can't explain it but i feels like my body wants to take short breath. So when my body takes short breathes i get scared and breathe for myself. Also at times my heart starts to pound but that could be because i get scared. I went to the doctor and he gave me Nexium and i have been taking it for about a week and a half and it started to make the breathing problem go away, but i forgot to take the pill for 2 days and its come back. The wierd thing is that when i don't think about the breathing problem and do stuff it feels as if i don't have one, but the second i start thinking about it, it comes back. The worst times are at night and that's when my heart pounds. Also at times i get really scared and goto the e.r and then it goes away right when i walk in. That's why the doctors think nothings wrong with me because it goes away once i walk into the building. Also once i started taking the nexium pills i don't swallow them i open the capsule and pour the pellets in my mouth and swallow them, i just can't swallow pills! After taking the pills about 3 days late my legs and arm started to feel numb for a day. Like there was not enough blood pumping in them. After that went away i started to have major back pain on my left upper side. It hurts so much that i can barely walk or sit. That goes away and comes back. The breathing problems kind of feel as if i have a very stuffy nose but i don't. Before this all happened i did have bad heartburn, especially at night. I just haven't been diagnosed with Acid Reflux or anything because i never really goto the doctor. When the breathing problems occur i sometimes feel like i need to burp but i can't and when i do burp it feels better, but only for a second. I really don't know what's wrong with me, im only 15 and i don't want to live a life worried about my breathing all the time. At times i feel like i'm going to die and i start to get sad and feel like that day is going to be my last. I go back to the doctor this week, but i'm scared he just going to say "your fine" and send me off. I don't feel fine and the doctor's can't see it. The last time i went which was a week ago he did a x-ray of my lungs and said everything was good and took blood. He still hasn't got back to me on my blood test but hopefully he'll find something wrong with me because i want this to be gone. Please respond and tell me what you think could be wrong with me. I'm thinking maybe Acid Reflux, GERD, Heart disease, Diabetes ( i do eat alott of sweets). I just want some answers. Thanks