I need help with anxiety and allergies, please help!?

Ok so for about the past two months now, (march 5th), it hasn't been going well at all. Something happened at my friends house, we were in his basement which has a dog, and i started to not be able to breathe. His mom made me take his inhaler for dogs and we went to the hospital. When I went there, they told me nothing was wrong with me. A week or two ago, I asked my dad to take me to the hospital again because of chest pains. AGAIN the doctor says absolutely nothing is wrong with me. X-rays were done, I was listened to for wheezing, and of course nothing was wrong. Prior to my second visit, is when everything got REALLY bad. I had panic attacks as a child and now they're coming back. This time, 10x worse. The main thing that is triggering them is my allergies, because i feel like they're going to make me suffocate or something silly like that. I have not been to an allergen yet, and have not been FULLY tested for asthma, but I was given an inhaler. Yesterday at school, I had nasty dry mouth all day. I mean to the extent where i was distracted every period 3 times or more worrying about drinking water. There were times when the dry mouth got really bad, and I literally could not swallow until running to a water fountain. I hoped this was a one time thing, I thought wrong. Today during 4th period, i started getting dry mouth. No problem, i would simply get a drink of water at the end of the period. All went well, but then i got to chorus class. Not only did I take a girls water bottle to refill for myself, but i was drinking it the whole time we were singing. Then, towards the end of the class, i started getting an excessive amount of phlegm (flem) in my throat. If i tried to hack it up and spit it out in a trash can or something, i would not be able to swallow after i did that and would cough crazily till i got water. I went to the nurses office where she took pretty good care of me, told me to take my inhaler, which virtually did absolutely did nothing. I drank , what i calculated to be close to a gallon of water in approximately an hour, and i was NOT dehydrated before this. Its getting scary at this point, and when my parents picked me up to take me home, it wasn't any better at home. I drank water all afternoon and have used the restroom to go pee at least 7 times. Why am i getting this dry mouth? How is the phlegm so serious that i feel like i can't breathe or swallow at times? WHAT SHOULD I DO? NO DOCTORS HAVE BEEN ABLE TO HELP ME AND I REALLY DO NEED HELP. Someone please tell me what to do. Thank you