Choking not caused by food/liquid, violent coughing attack, thick mucus, eyes turn red, weight loss, chest pain; my dr can’t find out what’s wrong?

Allergic response... Symptoms consistent with Allergic Response, probably to Environmental Allergens. Weight loss is probably due to not eating enough due to 'Choking' feeling; since one is not inclined to want to eat if they anticipate 'choking'. A Pulmonary consult or Allergist could help identify the cause of the Symptoms.
Aspiration. Even small quantities of fluid or food can cause the airway to become inflamed, infected or reactive. If you are still symptomatic I would suggest a Pulmonary evaluation, including PFTs and a Chest radiograph. Weight loss may or may not be related.
Other possible causes that can contribute include allergies and reflux. A virtual consultation is available and may be useful to you and your M.D.