Could This Be Asthma Related Or Something Else?

For the past 4 days ive been having some difficulty breathing I feel like I cant catch my breath at times or I take shallow breaths or very deep breaths very little tightness more of the feeling that I just cant catch my breath..No wheezing involved..Ive been checking my peak flow and its between 450-500 which when I was in the er and got 450 dr said it was normal thats hasnt changed its been consitantly 450-500 before this started I had either a severe allergy attack or a cold I had stuffy nose runny nose sneezing headache ear pressure then after all that stoped thats when this started now I have the breathing problems headache with a lightheadness and ear pressure at times for 2 nights I tried my rescue inhaler and that didnt seem to make a difference and I just tried it again when I got woke up and didnt make a huge difference I dont feel it all the time but its here a good majority of the day after I took the inhaler I checked my peak flow it was still the same value.
I dunno if this could be asthma related considering its been 4 days no wheezing and my peak flow is normal and consisitant or if it has to do with the allergy attack or cold I had or if its constant anxiety..I cant go to the dr cause im under no insurance yet and ive been to the er twice in the past 2 months for a similar feeling and they found nothing wrong so what do you guys think it can be and what do reccomend I can do

when i feel it then i guess i do go into more anxiety its on and off all day but more on then off im on nothing for anxiety right now i have no insurance i was on xanax for about a week but felt worse on it after 4 days and im currently taking nothign for asthma i have a xopenex rescue inhaler and ive used it a few times during this and i dont really feel a difference after it and theres no difference in my peak flow after i use it

There is something called "air hunger" that could be related to low thyroid.