What causes fullness feeling in throat and shortness of breath?

Possibly reflux. Stomach juice can come into the throat causing the symptoms you describe. Sleep with the lower part of your neck elevated above your abdomen (semi-sitting). Do not eat or drink anything for 3 hours prior to going to bed. Take Prilosec otc before breakfast and Zantac (ranitidine) 150 before dinner. No coffee, tea, soda, tomatoe products. If you are not better within 2 weeks see an ENT doctor.
Possible reflux. If this occurs with eating, this may be a symptom of reflux and esophageal spasms. It would help to know when your symptoms occur.

Related Questions

Can chronic sinusitis cause throat swelling sensation and fullness and shortness of breath?

Not necessarily. Chronic rhinosinusitis can lead to an asthma flare, and a sense of sinus fullness. However, if you are having throat swelling, it can be due to angioedema or to a severe allergic reaction. You should see an allergist as soon as possible. If it happens again, go to your emergency room - this can be life threatening.
Yes. Chronic sinusitis is an inflammatory condition that results in the secretion of lots of chemicals that cause and increase inflammation. These chemicals often spill out of the sinuses and drain down the back of the throat, and can cause the sensations you describe. Topical treatments such as mouthwashes can make it feel better, but you need to see your doctor to get the chronic sinusitis addressed.