Back of nose feels blocked when i breathe and swallow. causes anxiety. feels like it's at the back of the roof of mouth? adenoids? epiglottis?

Hard to know: Congestion is often due to chronic rhinits, maybe from allergy, irritants, structural problem, infection, hormone changes, sensitivity to weather/pressure changes etc. Often, post-nasal drip occurs and this is irritating to the back of the throat, causing symptom called globus pharyngis. I think your description is consistent. Acid reflux is another common cause. This can be confirmed and treated.