I was in a car accident last week and had to have a chest xray done because of impact issues. (Just slight rib bruising, I'm okay.) I vape a reduced PG blend, which has glycerin in it. My lungs looked great according to the doctor.
If glycerine is the problem switch to straight PG. Most e liquid out there is PG.
I think you should get a second opinion and ask more questions. Just because someone is a doctor, doesn't make them infallible. Question with boldness and arm yourself with knowledge.
Example: My son's pediatrician, for months, told me he was just having growing pains, when he would have spells of not being able to walk for hours. He was in tremendous pain. The doctor said he was big for his age and his growth plates were hurting him. They took xrays to make me feel better. Low and behold, he spiked a 104 fever and after 400mg of motrin, the fever wouldn't break and he was having a spell of leg pain all day. I took him to the ER, they did blood work. Turns out he had Acute Lymphocitic Leukemia. He is fine now, thanks to St. Jude. But after the diagnosis, I called the pediatrician, told him what was going on, and before he could make excuses for not running simple blood work, I fired him.