Okay, well let's sort out your questions and concerns.

Firstly, be aware that the onset of palpitations does not arise from the detection of stressful or anxiety-provoking circumstances, but rather because the chronic presence of anxiety in general has caused your nervous system to be more sensitive. The parasympathetic nervous system is responsible for invoking a vagus nerve response upon the heart, in essence telling it to slow down. The reason you feel the "thump" and the sensation in your throat is because the heart is not necessarily in need of slowing down, but nevertheless responds to the neurotransmitter response by the vagus nerve. It is a dysregulation of the nervous system activity known as "fight or flight" and comes about as a consequence of increased stress and anxiety.

You don't have to be active for the palpitations to occur. In fact, many patients actually experience more palpitations when lying down or in the absence of activity. It's not a factor requiring movement or action, but rather the status of your nervous system.

Secondly, you don't have to necessarily eat anything for your digestive system to become stimulated. Missed meals can produce the same general effects as well. Even if you just arose from sleep, the stomach will actually be stimulated, as well as the intestinal tract. If you happen to have had trapped air in the lumen of the intestines or stomach during sleep, then changing position or rising from sleep can cause the same sort of stimulation necessary for the Vagus nerve to send a signal outward.

Shallow breathing is very common among those with anxiety and accounts many times for the onset of panic due to the changes in blood gases, particularly CO2. Patients will often complain of feeling like they are unable to take an "inspriational" breath, or the automatic and irregular deep breath experienced by most folks. In response, some people begin focusing on this phenomenon and intentionally try to take an extraordinarily large breath to bring about relaxation. If they are unable, they begin to feel that they cannot get enough air and begin to panic, sometimes feeling as though their throat is closing off, a phenomenon known as Globus Hystericus. Panic thresholds are quite common subsequent to such efforts.

Becoming aware of, and focusing upon, autonomic processes very often creates vigilence in many anxiety sufferers and they feel that they must constantly check and monitor heart rate and respiration for signs of change. In fact, their focus actually induces change in some instances and provides a feedback that only serves to make matters worse.  

Benign palpitations of the type you are experiencing are entirely harmless. They will never damage your heart nor reduce your life span by even a moment. There is also nothing that can change the status of the palpitations from benign to pathological. They are only a symptom of nervous stimulation due to an anxiety disorder. You need to keep in mind that this kind of ectopic occurrence does not originate from within the heart as it would in the instance of true heart disease.

As I've said to many folks here on the forum, in more than 40 years of practice I've never even once heard of a person suffering any type of cardiac event as a result of heart palpitations of the type you and others here are experiencing. Not once. Your case is no different. You will never come to any harm as a result of the palpitations. They are not occuring because something is wrong with your heart in any manner whatsoever. Anxiety symptoms do not equate with physical disease.

You're going to be just fine.

Best regards and Good Health