I'm so sorry you are having such awful breathing problems! And your doctor seems to think your situation is normal! Has he given you any tests? My husband had lung cancer and was often very breathless. What helped him was home oxygen. Also he had a nebulizer machine that you put medicine in and then breathe in the fumes for about 5 minutes. He had hand held inhalers too. All of these helped his breathing. They all require a doctor's prescription. Ask your doctor about them. If he doesn't want to give them to you then perhaps you need to find a new doctor. It's your body and your money. The doctors are supposed to be here to help you.

Research all the side effects of your medications and over the counter medications. Often the side effects can cause breathlessness.

Prayer also helps. Just talk to God like he's your best friend and he is! God made you and he can fix you! I'll say a prayer for you also.
I wish you the best.
PML