Welcome to the forum! Please listen to Kitt and make an appointment. If you have an asthma/allergy doctor, that would probably be a great option, as he/she will be knowledgeable regarding your lung symptoms as well as the possiblity that reflux can be exacerbating your symptoms.
If you have asthma, you know that lung symptoms can continue long after a cold or allergy exposure. Yes, acid reflux can make things even worse. Morning phlegm and lung mucous is common with lung and throat irritation.
Please make an appointment, and let us know what you find out.
Very best wishes,
Words of wisdom by Eckhart Tolle:
"Whatever you fight, you strengthen, and what you resist, persists.”
“Worry pretends to be necessary but serves no useful purpose”
“Accept - then act. Whatever the present moment contains, accept it as if you had chosen it. Always work with it, not against it.”