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